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SSH2 channel fix: received WINDOW_ADJUSTs were always applied to the
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
3cd52910 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 23 (s ? sk_close(s), s = NULL : 0), \
3cd52910 24 connection_fatal msg )
8d5de777 25
d211621f 26#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29#define SSH1_CMSG_USER 4 /* 0x4 */
30#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38#define SSH1_SMSG_SUCCESS 14 /* 0xe */
39#define SSH1_SMSG_FAILURE 15 /* 0xf */
40#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43#define SSH1_CMSG_EOF 19 /* 0x13 */
44#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 50#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 53#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 55#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 56#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 59#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 60#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 61#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67
68#define SSH1_AUTH_TIS 5 /* 0x5 */
69#define SSH1_AUTH_CCARD 16 /* 0x10 */
70
b96dc54c 71#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72/* Mask for protoflags we will echo back to server if seen */
73#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
74
d211621f 75#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76#define SSH2_MSG_IGNORE 2 /* 0x2 */
77#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78#define SSH2_MSG_DEBUG 4 /* 0x4 */
79#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81#define SSH2_MSG_KEXINIT 20 /* 0x14 */
82#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
a92dd380 85#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
d211621f 89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
9005f3ba 110#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
121
d211621f 122#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
123#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
124#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
125#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
126
127#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 128
7d503c31 129/*
130 * Various remote-bug flags.
131 */
132#define BUG_CHOKES_ON_SSH1_IGNORE 1
133#define BUG_SSH2_HMAC 2
134
fb09bf1c 135#define GET_32BIT(cp) \
136 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
137 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
138 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
139 ((unsigned long)(unsigned char)(cp)[3]))
140
141#define PUT_32BIT(cp, value) { \
142 (cp)[0] = (unsigned char)((value) >> 24); \
143 (cp)[1] = (unsigned char)((value) >> 16); \
144 (cp)[2] = (unsigned char)((value) >> 8); \
145 (cp)[3] = (unsigned char)(value); }
146
7cca0d81 147enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 148
374330e2 149/* Coroutine mechanics for the sillier bits of the code */
150#define crBegin1 static int crLine = 0;
151#define crBegin2 switch(crLine) { case 0:;
152#define crBegin crBegin1; crBegin2;
153#define crFinish(z) } crLine = 0; return (z)
154#define crFinishV } crLine = 0; return
155#define crReturn(z) \
156 do {\
157 crLine=__LINE__; return (z); case __LINE__:;\
158 } while (0)
159#define crReturnV \
160 do {\
161 crLine=__LINE__; return; case __LINE__:;\
162 } while (0)
163#define crStop(z) do{ crLine = 0; return (z); }while(0)
164#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 165#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 166#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 167
0c6c9a70 168extern char *x11_init (Socket *, char *, void *);
9c964e85 169extern void x11_close (Socket);
170extern void x11_send (Socket , char *, int);
171extern void x11_invent_auth(char *, int, char *, int);
172
5e8358ad 173/*
174 * Ciphers for SSH2. We miss out single-DES because it isn't
175 * supported; also 3DES and Blowfish are both done differently from
176 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
177 * endianness and different-sized keys.)
5e8358ad 178 */
0a3f1d48 179const static struct ssh2_ciphers *ciphers[] = {
180 &ssh2_aes,
181 &ssh2_blowfish,
182 &ssh2_3des,
8479e33c 183};
e5574168 184
a92dd380 185const static struct ssh_kex *kex_algs[] = {
a92dd380 186 &ssh_diffiehellman_gex,
a92dd380 187 &ssh_diffiehellman };
e5574168 188
85cc02bb 189const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 190
d39f364a 191static void nullmac_key(unsigned char *key) { }
e5574168 192static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
193static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 194const static struct ssh_mac ssh_mac_none = {
d39f364a 195 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 196};
8b2715b2 197const static struct ssh_mac *macs[] = {
198 &ssh_sha1, &ssh_md5, &ssh_mac_none };
199const static struct ssh_mac *buggymacs[] = {
200 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 201
4ba9b64b 202static void ssh_comp_none_init(void) { }
203static int ssh_comp_none_block(unsigned char *block, int len,
204 unsigned char **outblock, int *outlen) {
205 return 0;
206}
63b00c83 207static int ssh_comp_none_disable(void) { return 0; }
57476f6b 208const static struct ssh_compress ssh_comp_none = {
4ba9b64b 209 "none",
210 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 211 ssh_comp_none_init, ssh_comp_none_block,
212 ssh_comp_none_disable
e5574168 213};
4ba9b64b 214extern const struct ssh_compress ssh_zlib;
215const static struct ssh_compress *compressions[] = {
216 &ssh_zlib, &ssh_comp_none };
374330e2 217
783415f8 218enum { /* channel types */
219 CHAN_MAINSESSION,
220 CHAN_X11,
221 CHAN_AGENT,
222};
223
dacbd0e8 224/*
225 * 2-3-4 tree storing channels.
226 */
227struct ssh_channel {
d211621f 228 unsigned remoteid, localid;
dacbd0e8 229 int type;
230 int closes;
783415f8 231 struct ssh2_data_channel {
232 unsigned char *outbuffer;
233 unsigned outbuflen, outbufsize;
234 unsigned remwindow, remmaxpkt;
235 } v2;
dacbd0e8 236 union {
237 struct ssh_agent_channel {
238 unsigned char *message;
239 unsigned char msglen[4];
240 int lensofar, totallen;
241 } a;
9c964e85 242 struct ssh_x11_channel {
243 Socket s;
783415f8 244 } x11;
dacbd0e8 245 } u;
246};
57476f6b 247
248struct Packet {
249 long length;
250 int type;
251 unsigned char *data;
252 unsigned char *body;
253 long savedpos;
254 long maxlen;
255};
256
0db56f73 257static SHA_State exhash, exhashbase;
57476f6b 258
8df7a775 259static Socket s = NULL;
57476f6b 260
261static unsigned char session_key[32];
4ba9b64b 262static int ssh1_compressing;
b96dc54c 263static int ssh1_remote_protoflags;
264static int ssh1_local_protoflags;
db7d555c 265static int ssh_agentfwd_enabled;
9c964e85 266static int ssh_X11_fwd_enabled;
7d503c31 267static int ssh_remote_bugs;
57476f6b 268static const struct ssh_cipher *cipher = NULL;
0a3f1d48 269static const struct ssh2_cipher *cscipher = NULL;
270static const struct ssh2_cipher *sccipher = NULL;
57476f6b 271static const struct ssh_mac *csmac = NULL;
272static const struct ssh_mac *scmac = NULL;
273static const struct ssh_compress *cscomp = NULL;
274static const struct ssh_compress *sccomp = NULL;
275static const struct ssh_kex *kex = NULL;
e055a386 276static const struct ssh_signkey *hostkey = NULL;
65a22376 277static unsigned char ssh2_session_id[20];
fa17a66e 278int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
279 int is_pw) = NULL;
57476f6b 280
281static char *savedhost;
282static int savedport;
283static int ssh_send_ok;
0965bee0 284static int ssh_echoing, ssh_editing;
57476f6b 285
dacbd0e8 286static tree234 *ssh_channels; /* indexed by local id */
57476f6b 287static struct ssh_channel *mainchan; /* primary session channel */
288
289static enum {
3687d221 290 SSH_STATE_PREPACKET,
57476f6b 291 SSH_STATE_BEFORE_SIZE,
292 SSH_STATE_INTERMED,
293 SSH_STATE_SESSION,
294 SSH_STATE_CLOSED
3687d221 295} ssh_state = SSH_STATE_PREPACKET;
57476f6b 296
3687d221 297static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 298
299static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
300static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 301static unsigned char *deferred_send_data = NULL;
302static int deferred_len = 0, deferred_size = 0;
57476f6b 303
304static int ssh_version;
305static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
306static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
307static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
308static void ssh_size(void);
3687d221 309static void ssh_special (Telnet_Special);
783415f8 310static void ssh2_try_send(struct ssh_channel *c);
311static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 312
313static int (*s_rdpkt)(unsigned char **data, int *datalen);
314
315static struct rdpkt1_state_tag {
316 long len, pad, biglen, to_read;
317 unsigned long realcrc, gotcrc;
318 unsigned char *p;
319 int i;
320 int chunk;
321} rdpkt1_state;
322
960e736a 323static struct rdpkt2_state_tag {
324 long len, pad, payload, packetlen, maclen;
325 int i;
326 int cipherblk;
327 unsigned long incoming_sequence;
328} rdpkt2_state;
329
dacbd0e8 330static int ssh_channelcmp(void *av, void *bv) {
331 struct ssh_channel *a = (struct ssh_channel *)av;
332 struct ssh_channel *b = (struct ssh_channel *)bv;
333 if (a->localid < b->localid) return -1;
334 if (a->localid > b->localid) return +1;
335 return 0;
336}
337static int ssh_channelfind(void *av, void *bv) {
d211621f 338 unsigned *a = (unsigned *)av;
dacbd0e8 339 struct ssh_channel *b = (struct ssh_channel *)bv;
340 if (*a < b->localid) return -1;
341 if (*a > b->localid) return +1;
342 return 0;
343}
344
374330e2 345static void c_write (char *buf, int len) {
67779be7 346 if ((flags & FLAG_STDERR)) {
4017be6d 347 int i;
348 for (i = 0; i < len; i++)
349 if (buf[i] != '\r')
350 fputc(buf[i], stderr);
fb09bf1c 351 return;
352 }
fe50e814 353 from_backend(1, buf, len);
3bdaf79d 354}
355
a209e957 356static void c_write_untrusted(char *buf, int len) {
357 int i;
358 for (i = 0; i < len; i++) {
359 if (buf[i] == '\n')
360 c_write("\r\n", 2);
361 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
362 c_write(buf+i, 1);
363 }
364}
365
1408a877 366static void c_write_str (char *buf) {
367 c_write(buf, strlen(buf));
368}
369
fb09bf1c 370/*
371 * Collect incoming data in the incoming packet buffer.
e5574168 372 * Decipher and verify the packet when it is completely read.
373 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 374 * Update the *data and *datalen variables.
375 * Return the additional nr of bytes needed, or 0 when
376 * a complete packet is available.
377 */
e5574168 378static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 379{
57476f6b 380 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 381
382 crBegin;
374330e2 383
fb09bf1c 384next_packet:
37508af4 385
fb09bf1c 386 pktin.type = 0;
387 pktin.length = 0;
374330e2 388
57476f6b 389 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 390 while ((*datalen) == 0)
57476f6b 391 crReturn(4-st->i);
392 st->len = (st->len << 8) + **data;
fb09bf1c 393 (*data)++, (*datalen)--;
394 }
374330e2 395
fb09bf1c 396#ifdef FWHACK
57476f6b 397 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
398 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 399 }
400#endif
374330e2 401
57476f6b 402 st->pad = 8 - (st->len % 8);
403 st->biglen = st->len + st->pad;
404 pktin.length = st->len - 5;
fb09bf1c 405
57476f6b 406 if (pktin.maxlen < st->biglen) {
407 pktin.maxlen = st->biglen;
dcbde236 408 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
409 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 410 if (!pktin.data)
411 fatalbox("Out of memory");
412 }
374330e2 413
57476f6b 414 st->to_read = st->biglen;
415 st->p = pktin.data;
416 while (st->to_read > 0) {
417 st->chunk = st->to_read;
fb09bf1c 418 while ((*datalen) == 0)
57476f6b 419 crReturn(st->to_read);
420 if (st->chunk > (*datalen))
421 st->chunk = (*datalen);
422 memcpy(st->p, *data, st->chunk);
423 *data += st->chunk;
424 *datalen -= st->chunk;
425 st->p += st->chunk;
426 st->to_read -= st->chunk;
fb09bf1c 427 }
374330e2 428
fb09bf1c 429 if (cipher)
57476f6b 430 cipher->decrypt(pktin.data, st->biglen);
698a5108 431#if 0
432 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
433 for (st->i = 0; st->i < st->biglen; st->i++)
434 debug((" %02x", (unsigned char)pktin.data[st->i]));
435 debug(("\r\n"));
436#endif
374330e2 437
57476f6b 438 st->realcrc = crc32(pktin.data, st->biglen-4);
439 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
440 if (st->gotcrc != st->realcrc) {
8d5de777 441 bombout(("Incorrect CRC received on packet"));
442 crReturn(0);
fb09bf1c 443 }
572f871e 444
4ba9b64b 445 pktin.body = pktin.data + st->pad + 1;
446
447 if (ssh1_compressing) {
448 unsigned char *decompblk;
449 int decomplen;
450#if 0
b96dc54c 451 {
452 int i;
453 debug(("Packet payload pre-decompression:\n"));
454 for (i = -1; i < pktin.length; i++)
455 debug((" %02x", (unsigned char)pktin.body[i]));
456 debug(("\r\n"));
457 }
4ba9b64b 458#endif
459 zlib_decompress_block(pktin.body-1, pktin.length+1,
460 &decompblk, &decomplen);
461
462 if (pktin.maxlen < st->pad + decomplen) {
463 pktin.maxlen = st->pad + decomplen;
dcbde236 464 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 465 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 466 if (!pktin.data)
467 fatalbox("Out of memory");
468 }
469
470 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 471 sfree(decompblk);
4ba9b64b 472 pktin.length = decomplen-1;
473#if 0
b96dc54c 474 {
475 int i;
476 debug(("Packet payload post-decompression:\n"));
477 for (i = -1; i < pktin.length; i++)
478 debug((" %02x", (unsigned char)pktin.body[i]));
479 debug(("\r\n"));
480 }
4ba9b64b 481#endif
482 }
483
e5574168 484 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
485 pktin.type == SSH1_SMSG_STDERR_DATA ||
486 pktin.type == SSH1_MSG_DEBUG ||
18515c51 487 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
488 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 489 long strlen = GET_32BIT(pktin.body);
8d5de777 490 if (strlen + 4 != pktin.length) {
491 bombout(("Received data packet with bogus string length"));
492 crReturn(0);
493 }
fb09bf1c 494 }
495
4ba9b64b 496 pktin.type = pktin.body[-1];
497
e5574168 498 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 499 /* log debug message */
500 char buf[80];
501 int strlen = GET_32BIT(pktin.body);
502 strcpy(buf, "Remote: ");
503 if (strlen > 70) strlen = 70;
504 memcpy(buf+8, pktin.body+4, strlen);
505 buf[8+strlen] = '\0';
506 logevent(buf);
507 goto next_packet;
e5574168 508 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 509 /* do nothing */
510 goto next_packet;
511 }
512
513 crFinish(0);
514}
515
e5574168 516static int ssh2_rdpkt(unsigned char **data, int *datalen)
517{
960e736a 518 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 519
520 crBegin;
521
522next_packet:
e5574168 523 pktin.type = 0;
524 pktin.length = 0;
960e736a 525 if (sccipher)
526 st->cipherblk = sccipher->blksize;
e5574168 527 else
960e736a 528 st->cipherblk = 8;
529 if (st->cipherblk < 8)
530 st->cipherblk = 8;
531
532 if (pktin.maxlen < st->cipherblk) {
533 pktin.maxlen = st->cipherblk;
dcbde236 534 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
535 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 536 if (!pktin.data)
537 fatalbox("Out of memory");
538 }
539
540 /*
541 * Acquire and decrypt the first block of the packet. This will
542 * contain the length and padding details.
543 */
960e736a 544 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 545 while ((*datalen) == 0)
960e736a 546 crReturn(st->cipherblk-st->i);
547 pktin.data[st->i] = *(*data)++;
e5574168 548 (*datalen)--;
549 }
550#ifdef FWHACK
551 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
552 /* FIXME */
553 }
554#endif
555 if (sccipher)
960e736a 556 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 557
558 /*
559 * Now get the length and padding figures.
560 */
960e736a 561 st->len = GET_32BIT(pktin.data);
562 st->pad = pktin.data[4];
e5574168 563
564 /*
565 * This enables us to deduce the payload length.
566 */
960e736a 567 st->payload = st->len - st->pad - 1;
e5574168 568
960e736a 569 pktin.length = st->payload + 5;
e5574168 570
571 /*
572 * So now we can work out the total packet length.
573 */
960e736a 574 st->packetlen = st->len + 4;
575 st->maclen = scmac ? scmac->len : 0;
e5574168 576
577 /*
578 * Adjust memory allocation if packet is too big.
579 */
960e736a 580 if (pktin.maxlen < st->packetlen+st->maclen) {
581 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 582 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
583 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 584 if (!pktin.data)
585 fatalbox("Out of memory");
586 }
587
588 /*
589 * Read and decrypt the remainder of the packet.
590 */
960e736a 591 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 592 while ((*datalen) == 0)
960e736a 593 crReturn(st->packetlen + st->maclen - st->i);
594 pktin.data[st->i] = *(*data)++;
e5574168 595 (*datalen)--;
596 }
597 /* Decrypt everything _except_ the MAC. */
598 if (sccipher)
960e736a 599 sccipher->decrypt(pktin.data + st->cipherblk,
600 st->packetlen - st->cipherblk);
e5574168 601
7cca0d81 602#if 0
960e736a 603 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
604 for (st->i = 0; st->i < st->packetlen; st->i++)
605 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 606 debug(("\r\n"));
7cca0d81 607#endif
d39f364a 608
e5574168 609 /*
610 * Check the MAC.
611 */
960e736a 612 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 613 bombout(("Incorrect MAC received on packet"));
614 crReturn(0);
615 }
960e736a 616 st->incoming_sequence++; /* whether or not we MACed */
e5574168 617
4ba9b64b 618 /*
619 * Decompress packet payload.
620 */
621 {
622 unsigned char *newpayload;
623 int newlen;
624 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
625 &newpayload, &newlen)) {
626 if (pktin.maxlen < newlen+5) {
627 pktin.maxlen = newlen+5;
dcbde236 628 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
629 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 630 if (!pktin.data)
631 fatalbox("Out of memory");
632 }
633 pktin.length = 5 + newlen;
634 memcpy(pktin.data+5, newpayload, newlen);
635#if 0
636 debug(("Post-decompression payload:\r\n"));
637 for (st->i = 0; st->i < newlen; st->i++)
638 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
639 debug(("\r\n"));
640#endif
641
dcbde236 642 sfree(newpayload);
4ba9b64b 643 }
644 }
645
e5574168 646 pktin.savedpos = 6;
647 pktin.type = pktin.data[5];
e5574168 648
7cca0d81 649 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
650 goto next_packet; /* FIXME: print DEBUG message */
e5574168 651
652 crFinish(0);
653}
654
4ba9b64b 655static void ssh1_pktout_size(int len) {
374330e2 656 int pad, biglen;
657
658 len += 5; /* type and CRC */
659 pad = 8 - (len%8);
660 biglen = len + pad;
661
662 pktout.length = len-5;
663 if (pktout.maxlen < biglen) {
664 pktout.maxlen = biglen;
8f203108 665#ifdef MSCRYPTOAPI
fb09bf1c 666 /* Allocate enough buffer space for extra block
8f203108 667 * for MS CryptEncrypt() */
dcbde236 668 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
669 srealloc(pktout.data, biglen+12));
8f203108 670#else
dcbde236 671 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
672 srealloc(pktout.data, biglen+4));
8f203108 673#endif
374330e2 674 if (!pktout.data)
675 fatalbox("Out of memory");
676 }
4ba9b64b 677 pktout.body = pktout.data+4+pad+1;
678}
374330e2 679
4ba9b64b 680static void s_wrpkt_start(int type, int len) {
681 ssh1_pktout_size(len);
374330e2 682 pktout.type = type;
374330e2 683}
684
39065bed 685static int s_wrpkt_prepare(void) {
374330e2 686 int pad, len, biglen, i;
687 unsigned long crc;
688
4ba9b64b 689 pktout.body[-1] = pktout.type;
690
7d503c31 691#if 0
692 debug(("Packet payload pre-compression:\n"));
693 for (i = -1; i < pktout.length; i++)
694 debug((" %02x", (unsigned char)pktout.body[i]));
695 debug(("\r\n"));
696#endif
697
4ba9b64b 698 if (ssh1_compressing) {
699 unsigned char *compblk;
700 int complen;
4ba9b64b 701 zlib_compress_block(pktout.body-1, pktout.length+1,
702 &compblk, &complen);
703 ssh1_pktout_size(complen-1);
704 memcpy(pktout.body-1, compblk, complen);
dcbde236 705 sfree(compblk);
4ba9b64b 706#if 0
707 debug(("Packet payload post-compression:\n"));
708 for (i = -1; i < pktout.length; i++)
709 debug((" %02x", (unsigned char)pktout.body[i]));
710 debug(("\r\n"));
711#endif
712 }
713
374330e2 714 len = pktout.length + 5; /* type and CRC */
715 pad = 8 - (len%8);
716 biglen = len + pad;
717
374330e2 718 for (i=0; i<pad; i++)
719 pktout.data[i+4] = random_byte();
720 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 721 PUT_32BIT(pktout.data+biglen, crc);
722 PUT_32BIT(pktout.data, len);
374330e2 723
698a5108 724#if 0
725 debug(("Sending packet len=%d\r\n", biglen+4));
726 for (i = 0; i < biglen+4; i++)
727 debug((" %02x", (unsigned char)pktout.data[i]));
728 debug(("\r\n"));
729#endif
374330e2 730 if (cipher)
731 cipher->encrypt(pktout.data+4, biglen);
732
39065bed 733 return biglen+4;
734}
735
736static void s_wrpkt(void) {
737 int len;
738 len = s_wrpkt_prepare();
739 sk_write(s, pktout.data, len);
740}
741
742static void s_wrpkt_defer(void) {
743 int len;
744 len = s_wrpkt_prepare();
745 if (deferred_len + len > deferred_size) {
746 deferred_size = deferred_len + len + 128;
747 deferred_send_data = srealloc(deferred_send_data, deferred_size);
748 }
749 memcpy(deferred_send_data+deferred_len, pktout.data, len);
750 deferred_len += len;
374330e2 751}
752
fb09bf1c 753/*
39065bed 754 * Construct a packet with the specified contents.
fb09bf1c 755 */
39065bed 756static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 757{
fb09bf1c 758 unsigned char *p, *argp, argchar;
759 unsigned long argint;
760 int pktlen, argtype, arglen;
7cca0d81 761 Bignum bn;
fb09bf1c 762
763 pktlen = 0;
39065bed 764 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 765 switch (argtype) {
766 case PKT_INT:
39065bed 767 (void) va_arg(ap1, int);
fb09bf1c 768 pktlen += 4;
769 break;
770 case PKT_CHAR:
39065bed 771 (void) va_arg(ap1, char);
fb09bf1c 772 pktlen++;
773 break;
774 case PKT_DATA:
39065bed 775 (void) va_arg(ap1, unsigned char *);
776 arglen = va_arg(ap1, int);
fb09bf1c 777 pktlen += arglen;
778 break;
779 case PKT_STR:
39065bed 780 argp = va_arg(ap1, unsigned char *);
fb09bf1c 781 arglen = strlen(argp);
782 pktlen += 4 + arglen;
783 break;
7cca0d81 784 case PKT_BIGNUM:
39065bed 785 bn = va_arg(ap1, Bignum);
5c58ad2d 786 pktlen += ssh1_bignum_length(bn);
7cca0d81 787 break;
fb09bf1c 788 default:
789 assert(0);
790 }
791 }
fb09bf1c 792
793 s_wrpkt_start(pkttype, pktlen);
794 p = pktout.body;
795
39065bed 796 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 797 switch (argtype) {
798 case PKT_INT:
39065bed 799 argint = va_arg(ap2, int);
fb09bf1c 800 PUT_32BIT(p, argint);
801 p += 4;
802 break;
803 case PKT_CHAR:
39065bed 804 argchar = va_arg(ap2, unsigned char);
fb09bf1c 805 *p = argchar;
806 p++;
807 break;
808 case PKT_DATA:
39065bed 809 argp = va_arg(ap2, unsigned char *);
810 arglen = va_arg(ap2, int);
fb09bf1c 811 memcpy(p, argp, arglen);
812 p += arglen;
813 break;
814 case PKT_STR:
39065bed 815 argp = va_arg(ap2, unsigned char *);
fb09bf1c 816 arglen = strlen(argp);
817 PUT_32BIT(p, arglen);
818 memcpy(p + 4, argp, arglen);
819 p += 4 + arglen;
820 break;
7cca0d81 821 case PKT_BIGNUM:
39065bed 822 bn = va_arg(ap2, Bignum);
5c58ad2d 823 p += ssh1_write_bignum(p, bn);
7cca0d81 824 break;
fb09bf1c 825 }
826 }
39065bed 827}
fb09bf1c 828
39065bed 829static void send_packet(int pkttype, ...) {
830 va_list ap1, ap2;
831 va_start(ap1, pkttype);
832 va_start(ap2, pkttype);
833 construct_packet(pkttype, ap1, ap2);
fb09bf1c 834 s_wrpkt();
835}
836
39065bed 837static void defer_packet(int pkttype, ...) {
838 va_list ap1, ap2;
839 va_start(ap1, pkttype);
840 va_start(ap2, pkttype);
841 construct_packet(pkttype, ap1, ap2);
842 s_wrpkt_defer();
843}
844
9697bfd2 845static int ssh_versioncmp(char *a, char *b) {
846 char *ae, *be;
847 unsigned long av, bv;
848
43aa02a7 849 av = strtoul(a, &ae, 10);
850 bv = strtoul(b, &be, 10);
9697bfd2 851 if (av != bv) return (av < bv ? -1 : +1);
852 if (*ae == '.') ae++;
853 if (*be == '.') be++;
43aa02a7 854 av = strtoul(ae, &ae, 10);
855 bv = strtoul(be, &be, 10);
9697bfd2 856 if (av != bv) return (av < bv ? -1 : +1);
857 return 0;
858}
859
e5574168 860
861/*
a92dd380 862 * Utility routines for putting an SSH-protocol `string' and
863 * `uint32' into a SHA state.
e5574168 864 */
865#include <stdio.h>
75cab814 866static void sha_string(SHA_State *s, void *str, int len) {
e5574168 867 unsigned char lenblk[4];
e5574168 868 PUT_32BIT(lenblk, len);
e5574168 869 SHA_Bytes(s, lenblk, 4);
e5574168 870 SHA_Bytes(s, str, len);
871}
872
a92dd380 873static void sha_uint32(SHA_State *s, unsigned i) {
874 unsigned char intblk[4];
875 PUT_32BIT(intblk, i);
876 SHA_Bytes(s, intblk, 4);
877}
878
7cca0d81 879/*
880 * SSH2 packet construction functions.
881 */
783415f8 882static void ssh2_pkt_ensure(int length) {
883 if (pktout.maxlen < length) {
884 pktout.maxlen = length + 256;
dcbde236 885 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
886 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 887 if (!pktout.data)
888 fatalbox("Out of memory");
889 }
783415f8 890}
891static void ssh2_pkt_adddata(void *data, int len) {
892 pktout.length += len;
893 ssh2_pkt_ensure(pktout.length);
7cca0d81 894 memcpy(pktout.data+pktout.length-len, data, len);
895}
75cab814 896static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 897 ssh2_pkt_adddata(&byte, 1);
898}
75cab814 899static void ssh2_pkt_init(int pkt_type) {
7cca0d81 900 pktout.length = 5;
901 ssh2_pkt_addbyte((unsigned char)pkt_type);
902}
75cab814 903static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 904 ssh2_pkt_adddata(&value, 1);
905}
75cab814 906static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 907 unsigned char x[4];
908 PUT_32BIT(x, value);
909 ssh2_pkt_adddata(x, 4);
910}
75cab814 911static void ssh2_pkt_addstring_start(void) {
7cca0d81 912 ssh2_pkt_adduint32(0);
913 pktout.savedpos = pktout.length;
914}
75cab814 915static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 916 ssh2_pkt_adddata(data, strlen(data));
917 PUT_32BIT(pktout.data + pktout.savedpos - 4,
918 pktout.length - pktout.savedpos);
919}
75cab814 920static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 921 ssh2_pkt_adddata(data, len);
922 PUT_32BIT(pktout.data + pktout.savedpos - 4,
923 pktout.length - pktout.savedpos);
924}
75cab814 925static void ssh2_pkt_addstring(char *data) {
7cca0d81 926 ssh2_pkt_addstring_start();
927 ssh2_pkt_addstring_str(data);
928}
75cab814 929static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 930 unsigned char *p;
3709bfe9 931 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
932 p = smalloc(n + 1);
7cca0d81 933 if (!p)
934 fatalbox("out of memory");
935 p[0] = 0;
3709bfe9 936 for (i = 1; i <= n; i++)
937 p[i] = bignum_byte(b, n-i);
7cca0d81 938 i = 0;
3709bfe9 939 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
7cca0d81 940 i++;
3709bfe9 941 memmove(p, p+i, n+1-i);
942 *len = n+1-i;
7cca0d81 943 return p;
944}
75cab814 945static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 946 unsigned char *p;
947 int len;
948 p = ssh2_mpint_fmt(b, &len);
949 ssh2_pkt_addstring_start();
950 ssh2_pkt_addstring_data(p, len);
dcbde236 951 sfree(p);
7cca0d81 952}
b185170a 953
954/*
955 * Construct an SSH2 final-form packet: compress it, encrypt it,
956 * put the MAC on it. Final packet, ready to be sent, is stored in
957 * pktout.data. Total length is returned.
958 */
959static int ssh2_pkt_construct(void) {
7cca0d81 960 int cipherblk, maclen, padding, i;
961 static unsigned long outgoing_sequence = 0;
962
963 /*
4ba9b64b 964 * Compress packet payload.
965 */
966#if 0
967 debug(("Pre-compression payload:\r\n"));
968 for (i = 5; i < pktout.length; i++)
969 debug((" %02x", (unsigned char)pktout.data[i]));
970 debug(("\r\n"));
971#endif
972 {
973 unsigned char *newpayload;
974 int newlen;
975 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
976 &newpayload, &newlen)) {
977 pktout.length = 5;
978 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 979 sfree(newpayload);
4ba9b64b 980 }
981 }
982
983 /*
7cca0d81 984 * Add padding. At least four bytes, and must also bring total
985 * length (minus MAC) up to a multiple of the block size.
986 */
8479e33c 987 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
7cca0d81 988 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
989 padding = 4;
990 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 991 maclen = csmac ? csmac->len : 0;
992 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 993 pktout.data[4] = padding;
994 for (i = 0; i < padding; i++)
995 pktout.data[pktout.length + i] = random_byte();
996 PUT_32BIT(pktout.data, pktout.length + padding - 4);
997 if (csmac)
998 csmac->generate(pktout.data, pktout.length + padding,
999 outgoing_sequence);
1000 outgoing_sequence++; /* whether or not we MACed */
1001
1002#if 0
1003 debug(("Sending packet len=%d\r\n", pktout.length+padding));
1004 for (i = 0; i < pktout.length+padding; i++)
1005 debug((" %02x", (unsigned char)pktout.data[i]));
1006 debug(("\r\n"));
1007#endif
1008
1009 if (cscipher)
1010 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1011
b185170a 1012 /* Ready-to-send packet starts at pktout.data. We return length. */
1013 return pktout.length + padding + maclen;
1014}
1015
1016/*
1017 * Construct and send an SSH2 packet immediately.
1018 */
1019static void ssh2_pkt_send(void) {
1020 int len = ssh2_pkt_construct();
1021 sk_write(s, pktout.data, len);
1022}
1023
1024/*
1025 * Construct an SSH2 packet and add it to a deferred data block.
1026 * Useful for sending multiple packets in a single sk_write() call,
1027 * to prevent a traffic-analysing listener from being able to work
1028 * out the length of any particular packet (such as the password
1029 * packet).
1030 *
1031 * Note that because SSH2 sequence-numbers its packets, this can
1032 * NOT be used as an m4-style `defer' allowing packets to be
1033 * constructed in one order and sent in another.
1034 */
1035static void ssh2_pkt_defer(void) {
1036 int len = ssh2_pkt_construct();
1037 if (deferred_len + len > deferred_size) {
1038 deferred_size = deferred_len + len + 128;
1039 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1040 }
1041 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1042 deferred_len += len;
1043}
1044
1045/*
1046 * Send the whole deferred data block constructed by
39065bed 1047 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1048 */
39065bed 1049static void ssh_pkt_defersend(void) {
b185170a 1050 sk_write(s, deferred_send_data, deferred_len);
1051 deferred_len = deferred_size = 0;
1052 sfree(deferred_send_data);
1053 deferred_send_data = NULL;
7cca0d81 1054}
1055
1056#if 0
1057void bndebug(char *string, Bignum b) {
1058 unsigned char *p;
1059 int i, len;
1060 p = ssh2_mpint_fmt(b, &len);
1061 debug(("%s", string));
1062 for (i = 0; i < len; i++)
1063 debug((" %02x", p[i]));
1064 debug(("\r\n"));
dcbde236 1065 sfree(p);
7cca0d81 1066}
1067#endif
1068
75cab814 1069static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 1070 unsigned char *p;
1071 int len;
1072 p = ssh2_mpint_fmt(b, &len);
1073 sha_string(s, p, len);
dcbde236 1074 sfree(p);
7cca0d81 1075}
1076
1077/*
1078 * SSH2 packet decode functions.
1079 */
75cab814 1080static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 1081 unsigned long value;
1082 if (pktin.length - pktin.savedpos < 4)
1083 return 0; /* arrgh, no way to decline (FIXME?) */
1084 value = GET_32BIT(pktin.data+pktin.savedpos);
1085 pktin.savedpos += 4;
1086 return value;
1087}
65a22376 1088static int ssh2_pkt_getbool(void) {
1089 unsigned long value;
1090 if (pktin.length - pktin.savedpos < 1)
1091 return 0; /* arrgh, no way to decline (FIXME?) */
1092 value = pktin.data[pktin.savedpos] != 0;
1093 pktin.savedpos++;
1094 return value;
1095}
75cab814 1096static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 1097 *p = NULL;
1098 if (pktin.length - pktin.savedpos < 4)
1099 return;
1100 *length = GET_32BIT(pktin.data+pktin.savedpos);
1101 pktin.savedpos += 4;
1102 if (pktin.length - pktin.savedpos < *length)
1103 return;
1104 *p = pktin.data+pktin.savedpos;
1105 pktin.savedpos += *length;
1106}
75cab814 1107static Bignum ssh2_pkt_getmp(void) {
7cca0d81 1108 char *p;
3709bfe9 1109 int length;
7cca0d81 1110 Bignum b;
1111
1112 ssh2_pkt_getstring(&p, &length);
1113 if (!p)
1114 return NULL;
8d5de777 1115 if (p[0] & 0x80) {
1116 bombout(("internal error: Can't handle negative mpints"));
1117 return NULL;
1118 }
3709bfe9 1119 b = bignum_from_bytes(p, length);
7cca0d81 1120 return b;
1121}
1122
7d503c31 1123/*
1124 * Examine the remote side's version string and compare it against
1125 * a list of known buggy implementations.
1126 */
1127static void ssh_detect_bugs(char *vstring) {
1128 char *imp; /* pointer to implementation part */
1129 imp = vstring;
1130 imp += strcspn(imp, "-");
1131 imp += strcspn(imp, "-");
1132
1133 ssh_remote_bugs = 0;
1134
1135 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1136 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1137 !strcmp(imp, "1.2.22")) {
1138 /*
1139 * These versions don't support SSH1_MSG_IGNORE, so we have
1140 * to use a different defence against password length
1141 * sniffing.
1142 */
1143 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1144 logevent("We believe remote version has SSH1 ignore bug");
1145 }
1146
1147 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1148 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1149 !strncmp(imp, "2.1 ", 4)) {
1150 /*
1151 * These versions have the HMAC bug.
1152 */
1153 ssh_remote_bugs |= BUG_SSH2_HMAC;
1154 logevent("We believe remote version has SSH2 HMAC bug");
1155 }
1156}
1157
8df7a775 1158static int do_ssh_init(unsigned char c) {
1159 static char *vsp;
1160 static char version[10];
1161 static char vstring[80];
1162 static char vlog[sizeof(vstring)+20];
1163 static int i;
374330e2 1164
8df7a775 1165 crBegin;
1166
1167 /* Search for the string "SSH-" in the input. */
374330e2 1168 i = 0;
8df7a775 1169 while (1) {
1170 static const int transS[] = { 1, 2, 2, 1 };
1171 static const int transH[] = { 0, 0, 3, 0 };
1172 static const int transminus[] = { 0, 0, 0, -1 };
1173 if (c == 'S') i = transS[i];
1174 else if (c == 'H') i = transH[i];
1175 else if (c == '-') i = transminus[i];
374330e2 1176 else i = 0;
8df7a775 1177 if (i < 0)
1178 break;
1179 crReturn(1); /* get another character */
374330e2 1180 }
8df7a775 1181
c5e9c988 1182 strcpy(vstring, "SSH-");
1183 vsp = vstring+4;
374330e2 1184 i = 0;
1185 while (1) {
8df7a775 1186 crReturn(1); /* get another char */
c5e9c988 1187 if (vsp < vstring+sizeof(vstring)-1)
1188 *vsp++ = c;
374330e2 1189 if (i >= 0) {
1190 if (c == '-') {
1191 version[i] = '\0';
1192 i = -1;
1193 } else if (i < sizeof(version)-1)
1194 version[i++] = c;
1195 }
1196 else if (c == '\n')
1197 break;
1198 }
1199
db7d555c 1200 ssh_agentfwd_enabled = FALSE;
960e736a 1201 rdpkt2_state.incoming_sequence = 0;
1202
c5e9c988 1203 *vsp = 0;
1204 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1205 ssh_detect_bugs(vstring);
c5e9c988 1206 vlog[strcspn(vlog, "\r\n")] = '\0';
1207 logevent(vlog);
1208
adf799dd 1209 /*
1210 * Server version "1.99" means we can choose whether we use v1
1211 * or v2 protocol. Choice is based on cfg.sshprot.
1212 */
1213 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1214 /*
1215 * This is a v2 server. Begin v2 protocol.
1216 */
900a4ee6 1217 char verstring[80];
1218 sprintf(verstring, "SSH-2.0-%s", sshver);
0db56f73 1219 SHA_Init(&exhashbase);
e5574168 1220 /*
1221 * Hash our version string and their version string.
1222 */
0db56f73 1223 sha_string(&exhashbase, verstring, strlen(verstring));
1224 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1225 sprintf(vstring, "%s\n", verstring);
1226 sprintf(vlog, "We claim version: %s", verstring);
1227 logevent(vlog);
1228 logevent("Using SSH protocol version 2");
8df7a775 1229 sk_write(s, vstring, strlen(vstring));
e5574168 1230 ssh_protocol = ssh2_protocol;
6abbf9e3 1231 ssh_version = 2;
e5574168 1232 s_rdpkt = ssh2_rdpkt;
1233 } else {
1234 /*
1235 * This is a v1 server. Begin v1 protocol.
1236 */
900a4ee6 1237 sprintf(vstring, "SSH-%s-%s\n",
1238 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1239 sshver);
e5574168 1240 sprintf(vlog, "We claim version: %s", vstring);
1241 vlog[strcspn(vlog, "\r\n")] = '\0';
1242 logevent(vlog);
1243 logevent("Using SSH protocol version 1");
8df7a775 1244 sk_write(s, vstring, strlen(vstring));
e5574168 1245 ssh_protocol = ssh1_protocol;
6abbf9e3 1246 ssh_version = 1;
e5574168 1247 s_rdpkt = ssh1_rdpkt;
1248 }
3687d221 1249 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1250
1251 crFinish(0);
1252}
1253
1254static void ssh_gotdata(unsigned char *data, int datalen)
1255{
1256 crBegin;
1257
1258 /*
1259 * To begin with, feed the characters one by one to the
1260 * protocol initialisation / selection function do_ssh_init().
1261 * When that returns 0, we're done with the initial greeting
1262 * exchange and can move on to packet discipline.
1263 */
1264 while (1) {
1265 int ret;
1266 if (datalen == 0)
1267 crReturnV; /* more data please */
1268 ret = do_ssh_init(*data);
1269 data++; datalen--;
1270 if (ret == 0)
1271 break;
1272 }
1273
1274 /*
1275 * We emerge from that loop when the initial negotiation is
1276 * over and we have selected an s_rdpkt function. Now pass
1277 * everything to s_rdpkt, and then pass the resulting packets
1278 * to the proper protocol handler.
1279 */
1280 if (datalen == 0)
1281 crReturnV;
1282 while (1) {
1283 while (datalen > 0) {
1284 if ( s_rdpkt(&data, &datalen) == 0 ) {
1285 ssh_protocol(NULL, 0, 1);
1286 if (ssh_state == SSH_STATE_CLOSED) {
1287 return;
1288 }
1289 }
1290 }
1291 crReturnV;
1292 }
1293 crFinishV;
1294}
1295
7e78000d 1296static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1297 ssh_state = SSH_STATE_CLOSED;
1298 sk_close(s);
1299 s = NULL;
1300 if (error_msg) {
2c94fd1c 1301 /* A socket error has occurred. */
7e78000d 1302 connection_fatal (error_msg);
1303 } else {
1304 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1305 }
7e78000d 1306 return 0;
1307}
1308
1309static int ssh_receive(Plug plug, int urgent, char *data, int len) {
8df7a775 1310 ssh_gotdata (data, len);
3257deae 1311 if (ssh_state == SSH_STATE_CLOSED) {
1312 if (s) {
1313 sk_close(s);
1314 s = NULL;
1315 }
1316 return 0;
1317 }
fef97f43 1318 return 1;
374330e2 1319}
1320
fb09bf1c 1321/*
8df7a775 1322 * Connect to specified host and port.
1323 * Returns an error message, or NULL on success.
1324 * Also places the canonical host name into `realhost'.
1325 */
1326static char *connect_to_host(char *host, int port, char **realhost)
1327{
7e78000d 1328 static struct plug_function_table fn_table = {
1329 ssh_closing,
1330 ssh_receive
1331 }, *fn_table_ptr = &fn_table;
1332
8df7a775 1333 SockAddr addr;
1334 char *err;
1335#ifdef FWHACK
1336 char *FWhost;
1337 int FWport;
1338#endif
1339
dcbde236 1340 savedhost = smalloc(1+strlen(host));
8df7a775 1341 if (!savedhost)
1342 fatalbox("Out of memory");
1343 strcpy(savedhost, host);
1344
1345 if (port < 0)
1346 port = 22; /* default ssh port */
1347 savedport = port;
1348
1349#ifdef FWHACK
1350 FWhost = host;
1351 FWport = port;
1352 host = FWSTR;
1353 port = 23;
1354#endif
1355
1356 /*
1357 * Try to find host.
1358 */
1359 addr = sk_namelookup(host, realhost);
1360 if ( (err = sk_addr_error(addr)) )
1361 return err;
1362
1363#ifdef FWHACK
1364 *realhost = FWhost;
1365#endif
1366
1367 /*
1368 * Open socket.
1369 */
7e78000d 1370 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
8df7a775 1371 if ( (err = sk_socket_error(s)) )
1372 return err;
1373
1374#ifdef FWHACK
1375 sk_write(s, "connect ", 8);
1376 sk_write(s, FWhost, strlen(FWhost));
1377 {
1378 char buf[20];
1379 sprintf(buf, " %d\n", FWport);
1380 sk_write(s, buf, strlen(buf));
1381 }
1382#endif
1383
1384 return NULL;
1385}
1386
1387/*
fb09bf1c 1388 * Handle the key exchange and user authentication phases.
1389 */
e5574168 1390static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1391{
374330e2 1392 int i, j, len;
374330e2 1393 unsigned char *rsabuf, *keystr1, *keystr2;
1394 unsigned char cookie[8];
1395 struct RSAKey servkey, hostkey;
1396 struct MD5Context md5c;
ccbfb941 1397 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1398 static int tried_publickey;
1399 static unsigned char session_id[16];
bea1ef5f 1400 int cipher_type;
b585ec46 1401 static char username[100];
374330e2 1402
374330e2 1403 crBegin;
1404
fb09bf1c 1405 if (!ispkt) crWaitUntil(ispkt);
374330e2 1406
8d5de777 1407 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1408 bombout(("Public key packet not received"));
1409 crReturn(0);
1410 }
374330e2 1411
c5e9c988 1412 logevent("Received public keys");
374330e2 1413
c5e9c988 1414 memcpy(cookie, pktin.body, 8);
374330e2 1415
7cca0d81 1416 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1417 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1418
c5e9c988 1419 /*
1c2a93c4 1420 * Log the host key fingerprint.
c5e9c988 1421 */
c5e9c988 1422 {
1423 char logmsg[80];
1c2a93c4 1424 logevent("Host key fingerprint is:");
c5e9c988 1425 strcpy(logmsg, " ");
1c2a93c4 1426 hostkey.comment = NULL;
1427 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1428 &hostkey);
c5e9c988 1429 logevent(logmsg);
1430 }
1431
b96dc54c 1432 ssh1_remote_protoflags = GET_32BIT(pktin.body+8+i+j);
fb09bf1c 1433 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1434 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1435
b96dc54c 1436 ssh1_local_protoflags = ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1437 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1438
c5e9c988 1439 MD5Init(&md5c);
374330e2 1440 MD5Update(&md5c, keystr2, hostkey.bytes);
1441 MD5Update(&md5c, keystr1, servkey.bytes);
1442 MD5Update(&md5c, pktin.body, 8);
374330e2 1443 MD5Final(session_id, &md5c);
1444
1445 for (i=0; i<32; i++)
1446 session_key[i] = random_byte();
1447
1448 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1449
dcbde236 1450 rsabuf = smalloc(len);
374330e2 1451 if (!rsabuf)
1452 fatalbox("Out of memory");
1453
89ee5268 1454 /*
1455 * Verify the host key.
1456 */
1457 {
1458 /*
1459 * First format the key into a string.
1460 */
1461 int len = rsastr_len(&hostkey);
d5859615 1462 char fingerprint[100];
dcbde236 1463 char *keystr = smalloc(len);
89ee5268 1464 if (!keystr)
1465 fatalbox("Out of memory");
1466 rsastr_fmt(keystr, &hostkey);
d5859615 1467 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1468 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1469 sfree(keystr);
89ee5268 1470 }
374330e2 1471
1472 for (i=0; i<32; i++) {
1473 rsabuf[i] = session_key[i];
1474 if (i < 16)
1475 rsabuf[i] ^= session_id[i];
1476 }
1477
1478 if (hostkey.bytes > servkey.bytes) {
1479 rsaencrypt(rsabuf, 32, &servkey);
1480 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1481 } else {
1482 rsaencrypt(rsabuf, 32, &hostkey);
1483 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1484 }
1485
c5e9c988 1486 logevent("Encrypted session key");
1487
0a3f1d48 1488 switch (cfg.cipher) {
1489 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1490 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1491 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1492 case CIPHER_AES:
1408a877 1493 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
0a3f1d48 1494 cipher_type = SSH_CIPHER_3DES;
1495 break;
1496 }
bea1ef5f 1497 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1408a877 1498 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
bea1ef5f 1499 cipher_type = SSH_CIPHER_3DES;
1500 }
c5e9c988 1501 switch (cipher_type) {
1502 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1503 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1504 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1505 }
bea1ef5f 1506
e5574168 1507 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1508 PKT_CHAR, cipher_type,
1509 PKT_DATA, cookie, 8,
1510 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1511 PKT_DATA, rsabuf, len,
b96dc54c 1512 PKT_INT, ssh1_local_protoflags,
fb09bf1c 1513 PKT_END);
1514
c5e9c988 1515 logevent("Trying to enable encryption...");
374330e2 1516
dcbde236 1517 sfree(rsabuf);
374330e2 1518
5e8358ad 1519 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1520 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1521 &ssh_3des;
374330e2 1522 cipher->sesskey(session_key);
1523
fb09bf1c 1524 crWaitUntil(ispkt);
374330e2 1525
8d5de777 1526 if (pktin.type != SSH1_SMSG_SUCCESS) {
1527 bombout(("Encryption not successfully enabled"));
1528 crReturn(0);
1529 }
374330e2 1530
c5e9c988 1531 logevent("Successfully started encryption");
1532
374330e2 1533 fflush(stdout);
1534 {
374330e2 1535 static int pos = 0;
1536 static char c;
67779be7 1537 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 1538 if (ssh_get_line) {
1539 if (!ssh_get_line("login as: ",
1540 username, sizeof(username), FALSE)) {
1541 /*
1542 * get_line failed to get a username.
1543 * Terminate.
1544 */
1545 logevent("No username provided. Abandoning session.");
1546 ssh_state = SSH_STATE_CLOSED;
1547 crReturn(1);
1548 }
1549 } else {
1550 c_write_str("login as: ");
1551 ssh_send_ok = 1;
1552 while (pos >= 0) {
1553 crWaitUntil(!ispkt);
1554 while (inlen--) switch (c = *in++) {
1555 case 10: case 13:
1556 username[pos] = 0;
1557 pos = -1;
1558 break;
1559 case 8: case 127:
1560 if (pos > 0) {
1561 c_write_str("\b \b");
1562 pos--;
1563 }
1564 break;
1565 case 21: case 27:
1566 while (pos > 0) {
1567 c_write_str("\b \b");
1568 pos--;
1569 }
1570 break;
1571 case 3: case 4:
1572 random_save_seed();
1573 exit(0);
1574 break;
1575 default:
1576 if (((c >= ' ' && c <= '~') ||
1577 ((unsigned char)c >= 160)) && pos < 40) {
1578 username[pos++] = c;
1579 c_write(&c, 1);
1580 }
1581 break;
1582 }
1583 }
1584 c_write_str("\r\n");
1585 username[strcspn(username, "\n\r")] = '\0';
1586 }
1587 } else {
374330e2 1588 strncpy(username, cfg.username, 99);
1589 username[99] = '\0';
374330e2 1590 }
fb09bf1c 1591
e5574168 1592 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1593 {
3c8e959b 1594 char userlog[22+sizeof(username)];
c5e9c988 1595 sprintf(userlog, "Sent username \"%s\"", username);
1596 logevent(userlog);
3c8e959b 1597 if (flags & FLAG_INTERACTIVE &&
1598 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1599 strcat(userlog, "\r\n");
1408a877 1600 c_write_str(userlog);
3c8e959b 1601 }
c5e9c988 1602 }
374330e2 1603 }
1604
fb09bf1c 1605 crWaitUntil(ispkt);
374330e2 1606
7cca0d81 1607 tried_publickey = 0;
1608
e5574168 1609 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1610 static char password[100];
a52f067e 1611 static char prompt[200];
374330e2 1612 static int pos;
1613 static char c;
ccbfb941 1614 static int pwpkt_type;
ccbfb941 1615 /*
1616 * Show password prompt, having first obtained it via a TIS
18515c51 1617 * or CryptoCard exchange if we're doing TIS or CryptoCard
1618 * authentication.
ccbfb941 1619 */
e5574168 1620 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1621 if (agent_exists()) {
1622 /*
1623 * Attempt RSA authentication using Pageant.
1624 */
1625 static unsigned char request[5], *response, *p;
1626 static int responselen;
1627 static int i, nkeys;
1628 static int authed = FALSE;
1629 void *r;
1630
1631 logevent("Pageant is running. Requesting keys.");
1632
1633 /* Request the keys held by the agent. */
1634 PUT_32BIT(request, 1);
1983e559 1635 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
5c58ad2d 1636 agent_query(request, 5, &r, &responselen);
1637 response = (unsigned char *)r;
95797139 1638 if (response && responselen >= 5 &&
1639 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
5c58ad2d 1640 p = response + 5;
1641 nkeys = GET_32BIT(p); p += 4;
6328ea7a 1642 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
5c58ad2d 1643 logevent(buf); }
1644 for (i = 0; i < nkeys; i++) {
1645 static struct RSAKey key;
1646 static Bignum challenge;
b8bb811a 1647 static char *commentp;
1648 static int commentlen;
5c58ad2d 1649
1650 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1651 logevent(buf); }
1652 p += 4;
1653 p += ssh1_read_bignum(p, &key.exponent);
1654 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1655 commentlen = GET_32BIT(p); p += 4;
1656 commentp = p; p += commentlen;
5c58ad2d 1657 send_packet(SSH1_CMSG_AUTH_RSA,
1658 PKT_BIGNUM, key.modulus, PKT_END);
1659 crWaitUntil(ispkt);
1660 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1661 logevent("Key refused");
1662 continue;
1663 }
1664 logevent("Received RSA challenge");
1665 ssh1_read_bignum(pktin.body, &challenge);
1666 {
1667 char *agentreq, *q, *ret;
1668 int len, retlen;
1669 len = 1 + 4; /* message type, bit count */
1670 len += ssh1_bignum_length(key.exponent);
1671 len += ssh1_bignum_length(key.modulus);
1672 len += ssh1_bignum_length(challenge);
1673 len += 16; /* session id */
1674 len += 4; /* response format */
dcbde236 1675 agentreq = smalloc(4 + len);
5c58ad2d 1676 PUT_32BIT(agentreq, len);
1677 q = agentreq + 4;
1983e559 1678 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
5c58ad2d 1679 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1680 q += 4;
1681 q += ssh1_write_bignum(q, key.exponent);
1682 q += ssh1_write_bignum(q, key.modulus);
1683 q += ssh1_write_bignum(q, challenge);
1684 memcpy(q, session_id, 16); q += 16;
1685 PUT_32BIT(q, 1); /* response format */
1686 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1687 sfree(agentreq);
5c58ad2d 1688 if (ret) {
1983e559 1689 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
5c58ad2d 1690 logevent("Sending Pageant's response");
1691 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1692 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1693 sfree(ret);
5c58ad2d 1694 crWaitUntil(ispkt);
1695 if (pktin.type == SSH1_SMSG_SUCCESS) {
1696 logevent("Pageant's response accepted");
c4fa2fce 1697 if (flags & FLAG_VERBOSE) {
1408a877 1698 c_write_str("Authenticated using RSA key \"");
c4fa2fce 1699 c_write(commentp, commentlen);
1408a877 1700 c_write_str("\" from agent\r\n");
c4fa2fce 1701 }
5c58ad2d 1702 authed = TRUE;
1703 } else
1704 logevent("Pageant's response not accepted");
1705 } else {
1706 logevent("Pageant failed to answer challenge");
dcbde236 1707 sfree(ret);
5c58ad2d 1708 }
1709 } else {
1710 logevent("No reply received from Pageant");
1711 }
1712 }
1713 freebn(key.exponent);
1714 freebn(key.modulus);
1715 freebn(challenge);
1716 if (authed)
1717 break;
1718 }
1719 }
1720 if (authed)
1721 break;
1722 }
7cca0d81 1723 if (*cfg.keyfile && !tried_publickey)
1724 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1725
a52f067e 1726 if (pktin.type == SSH1_SMSG_FAILURE &&
1727 cfg.try_tis_auth &&
1728 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1729 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1730 logevent("Requested TIS authentication");
1731 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1732 crWaitUntil(ispkt);
1733 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1734 logevent("TIS authentication declined");
1735 if (flags & FLAG_INTERACTIVE)
1408a877 1736 c_write_str("TIS authentication refused.\r\n");
a52f067e 1737 } else {
1738 int challengelen = ((pktin.body[0] << 24) |
1739 (pktin.body[1] << 16) |
1740 (pktin.body[2] << 8) |
1741 (pktin.body[3]));
1742 logevent("Received TIS challenge");
1743 if (challengelen > sizeof(prompt)-1)
1744 challengelen = sizeof(prompt)-1; /* prevent overrun */
1745 memcpy(prompt, pktin.body+4, challengelen);
1746 prompt[challengelen] = '\0';
1747 }
1748 }
1749 if (pktin.type == SSH1_SMSG_FAILURE &&
1750 cfg.try_tis_auth &&
1751 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1752 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1753 logevent("Requested CryptoCard authentication");
1754 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1755 crWaitUntil(ispkt);
1756 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1757 logevent("CryptoCard authentication declined");
1408a877 1758 c_write_str("CryptoCard authentication refused.\r\n");
a52f067e 1759 } else {
1760 int challengelen = ((pktin.body[0] << 24) |
1761 (pktin.body[1] << 16) |
1762 (pktin.body[2] << 8) |
1763 (pktin.body[3]));
1764 logevent("Received CryptoCard challenge");
1765 if (challengelen > sizeof(prompt)-1)
1766 challengelen = sizeof(prompt)-1; /* prevent overrun */
1767 memcpy(prompt, pktin.body+4, challengelen);
1768 strncpy(prompt + challengelen, "\r\nResponse : ",
1769 sizeof(prompt)-challengelen);
1770 prompt[sizeof(prompt)-1] = '\0';
1771 }
1772 }
1773 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1774 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1775 username, savedhost);
a52f067e 1776 }
1777 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1778 char *comment = NULL;
1779 if (flags & FLAG_VERBOSE)
1408a877 1780 c_write_str("Trying public key authentication.\r\n");
a52f067e 1781 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1782 if (flags & FLAG_VERBOSE)
1408a877 1783 c_write_str("No passphrase required.\r\n");
a52f067e 1784 goto tryauth;
1785 }
1786 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1787 sfree(comment);
a52f067e 1788 }
1789
fa17a66e 1790 if (ssh_get_line) {
1791 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
85ee8208 1792 /*
fa17a66e 1793 * get_line failed to get a password (for example
1794 * because one was supplied on the command line
1795 * which has already failed to work). Terminate.
85ee8208 1796 */
1797 logevent("No more passwords to try");
1798 ssh_state = SSH_STATE_CLOSED;
1799 crReturn(1);
1800 }
fb09bf1c 1801 } else {
1408a877 1802 c_write_str(prompt);
7cca0d81 1803 pos = 0;
67779be7 1804 ssh_send_ok = 1;
7cca0d81 1805 while (pos >= 0) {
1806 crWaitUntil(!ispkt);
1807 while (inlen--) switch (c = *in++) {
1808 case 10: case 13:
1809 password[pos] = 0;
1810 pos = -1;
1811 break;
1812 case 8: case 127:
1813 if (pos > 0)
1814 pos--;
1815 break;
1816 case 21: case 27:
1817 pos = 0;
1818 break;
1819 case 3: case 4:
1820 random_save_seed();
1821 exit(0);
1822 break;
1823 default:
1824 if (((c >= ' ' && c <= '~') ||
1825 ((unsigned char)c >= 160)) && pos < sizeof(password))
1826 password[pos++] = c;
1827 break;
1828 }
1829 }
1408a877 1830 c_write_str("\r\n");
a52f067e 1831 }
fb09bf1c 1832
7cca0d81 1833 tryauth:
1834 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1835 /*
1836 * Try public key authentication with the specified
1837 * key file.
1838 */
1839 static struct RSAKey pubkey;
1840 static Bignum challenge, response;
1841 static int i;
1842 static unsigned char buffer[32];
1843
1844 tried_publickey = 1;
65a22376 1845 i = loadrsakey(cfg.keyfile, &pubkey, password);
7cca0d81 1846 if (i == 0) {
1408a877 1847 c_write_str("Couldn't load public key from ");
1848 c_write_str(cfg.keyfile);
1849 c_write_str(".\r\n");
7cca0d81 1850 continue; /* go and try password */
1851 }
1852 if (i == -1) {
1408a877 1853 c_write_str("Wrong passphrase.\r\n");
7cca0d81 1854 tried_publickey = 0;
1855 continue; /* try again */
1856 }
1857
1858 /*
1859 * Send a public key attempt.
1860 */
1861 send_packet(SSH1_CMSG_AUTH_RSA,
1862 PKT_BIGNUM, pubkey.modulus, PKT_END);
1863
1864 crWaitUntil(ispkt);
1865 if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 1866 c_write_str("Server refused our public key.\r\n");
7cca0d81 1867 continue; /* go and try password */
1868 }
8d5de777 1869 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1870 bombout(("Bizarre response to offer of public key"));
1871 crReturn(0);
1872 }
7cca0d81 1873 ssh1_read_bignum(pktin.body, &challenge);
1874 response = rsadecrypt(challenge, &pubkey);
1875 freebn(pubkey.private_exponent); /* burn the evidence */
1876
3709bfe9 1877 for (i = 0; i < 32; i++) {
1878 buffer[i] = bignum_byte(response, 31-i);
7cca0d81 1879 }
1880
1881 MD5Init(&md5c);
1882 MD5Update(&md5c, buffer, 32);
1883 MD5Update(&md5c, session_id, 16);
1884 MD5Final(buffer, &md5c);
1885
1886 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1887 PKT_DATA, buffer, 16, PKT_END);
1888
1889 crWaitUntil(ispkt);
1890 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1891 if (flags & FLAG_VERBOSE)
1408a877 1892 c_write_str("Failed to authenticate with our public key.\r\n");
7cca0d81 1893 continue; /* go and try password */
1894 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1895 bombout(("Bizarre response to RSA authentication response"));
1896 crReturn(0);
7cca0d81 1897 }
1898
1899 break; /* we're through! */
1900 } else {
39065bed 1901 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1902 /*
1903 * Defence against traffic analysis: we send a
1904 * whole bunch of packets containing strings of
1905 * different lengths. One of these strings is the
1906 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1907 * The others are all random data in
1908 * SSH1_MSG_IGNORE packets. This way a passive
1909 * listener can't tell which is the password, and
1910 * hence can't deduce the password length.
1911 *
1912 * Anybody with a password length greater than 16
1913 * bytes is going to have enough entropy in their
1914 * password that a listener won't find it _that_
1915 * much help to know how long it is. So what we'll
1916 * do is:
1917 *
1918 * - if password length < 16, we send 15 packets
1919 * containing string lengths 1 through 15
1920 *
1921 * - otherwise, we let N be the nearest multiple
1922 * of 8 below the password length, and send 8
1923 * packets containing string lengths N through
1924 * N+7. This won't obscure the order of
1925 * magnitude of the password length, but it will
1926 * introduce a bit of extra uncertainty.
7d503c31 1927 *
1928 * A few servers (the old 1.2.18 through 1.2.22)
1929 * can't deal with SSH1_MSG_IGNORE. For these
1930 * servers, we need an alternative defence. We make
1931 * use of the fact that the password is interpreted
1932 * as a C string: so we can append a NUL, then some
1933 * random data.
39065bed 1934 */
7d503c31 1935 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
1936 char string[64];
1937 char *s;
1938 int len;
1939
1940 len = strlen(password);
1941 if (len < sizeof(string)) {
1942 s = string;
1943 strcpy(string, password);
1944 len++; /* cover the zero byte */
1945 while (len < sizeof(string)) {
1946 string[len++] = (char)random_byte();
1947 }
1948 } else {
1949 s = password;
1950 }
1951 send_packet(pwpkt_type, PKT_INT, len,
1952 PKT_DATA, s, len, PKT_END);
39065bed 1953 } else {
7d503c31 1954 int bottom, top, pwlen, i;
1955 char *randomstr;
1956
1957 pwlen = strlen(password);
1958 if (pwlen < 16) {
98c84eb4 1959 bottom = 0; /* zero length passwords are OK! :-) */
7d503c31 1960 top = 15;
1961 } else {
1962 bottom = pwlen &~ 7;
1963 top = bottom + 7;
1964 }
39065bed 1965
7d503c31 1966 assert(pwlen >= bottom && pwlen <= top);
39065bed 1967
7d503c31 1968 randomstr = smalloc(top+1);
39065bed 1969
7d503c31 1970 for (i = bottom; i <= top; i++) {
1971 if (i == pwlen)
1972 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
1973 else {
1974 for (j = 0; j < i; j++) {
1975 do {
1976 randomstr[j] = random_byte();
1977 } while (randomstr[j] == '\0');
1978 }
1979 randomstr[i] = '\0';
1980 defer_packet(SSH1_MSG_IGNORE,
1981 PKT_STR, randomstr, PKT_END);
39065bed 1982 }
39065bed 1983 }
7d503c31 1984 ssh_pkt_defersend();
39065bed 1985 }
39065bed 1986 } else {
1987 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1988 }
7cca0d81 1989 }
c5e9c988 1990 logevent("Sent password");
374330e2 1991 memset(password, 0, strlen(password));
fb09bf1c 1992 crWaitUntil(ispkt);
e5574168 1993 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1994 if (flags & FLAG_VERBOSE)
1408a877 1995 c_write_str("Access denied\r\n");
c5e9c988 1996 logevent("Authentication refused");
e5574168 1997 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1998 logevent("Received disconnect request");
85ee8208 1999 ssh_state = SSH_STATE_CLOSED;
2000 crReturn(1);
e5574168 2001 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2002 bombout(("Strange packet received, type %d", pktin.type));
2003 crReturn(0);
374330e2 2004 }
2005 }
2006
c5e9c988 2007 logevent("Authentication successful");
2008
fb09bf1c 2009 crFinish(1);
2010}
2011
9c964e85 2012void sshfwd_close(struct ssh_channel *c) {
80e48603 2013 if (c && !c->closes) {
783415f8 2014 if (ssh_version == 1) {
2015 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
2016 } else {
2017 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2018 ssh2_pkt_adduint32(c->remoteid);
2019 ssh2_pkt_send();
2020 }
2021 c->closes = 1;
2022 if (c->type == CHAN_X11) {
2023 c->u.x11.s = NULL;
2024 logevent("X11 connection terminated");
2025 }
2026 }
9c964e85 2027}
2028
2029void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 2030 if (ssh_version == 1) {
2031 send_packet(SSH1_MSG_CHANNEL_DATA,
2032 PKT_INT, c->remoteid,
2033 PKT_INT, len,
2034 PKT_DATA, buf, len,
2035 PKT_END);
2036 } else {
2037 ssh2_add_channel_data(c, buf, len);
2038 ssh2_try_send(c);
2039 }
9c964e85 2040}
2041
e5574168 2042static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 2043 crBegin;
2044
2045 random_init();
2046
e5574168 2047 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2048 crReturnV;
85ee8208 2049 }
2050 if (ssh_state == SSH_STATE_CLOSED)
2051 crReturnV;
fb09bf1c 2052
979310f1 2053 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 2054 logevent("Requesting agent forwarding");
2055 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2056 do { crReturnV; } while (!ispkt);
2057 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2058 bombout(("Protocol confusion"));
2059 crReturnV;
dacbd0e8 2060 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2061 logevent("Agent forwarding refused");
db7d555c 2062 } else {
dacbd0e8 2063 logevent("Agent forwarding enabled");
db7d555c 2064 ssh_agentfwd_enabled = TRUE;
2065 }
dacbd0e8 2066 }
2067
9c964e85 2068 if (cfg.x11_forward) {
2069 char proto[20], data[64];
2070 logevent("Requesting X11 forwarding");
2071 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
b96dc54c 2072 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2073 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2074 PKT_STR, proto, PKT_STR, data,
2075 PKT_INT, 0,
2076 PKT_END);
2077 } else {
2078 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2079 PKT_STR, proto, PKT_STR, data,
2080 PKT_END);
2081 }
9c964e85 2082 do { crReturnV; } while (!ispkt);
2083 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2084 bombout(("Protocol confusion"));
2085 crReturnV;
2086 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2087 logevent("X11 forwarding refused");
2088 } else {
2089 logevent("X11 forwarding enabled");
2090 ssh_X11_fwd_enabled = TRUE;
2091 }
2092 }
2093
fef97f43 2094 if (!cfg.nopty) {
e5574168 2095 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 2096 PKT_STR, cfg.termtype,
2097 PKT_INT, rows, PKT_INT, cols,
2098 PKT_INT, 0, PKT_INT, 0,
2099 PKT_CHAR, 0,
2100 PKT_END);
fef97f43 2101 ssh_state = SSH_STATE_INTERMED;
2102 do { crReturnV; } while (!ispkt);
e5574168 2103 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2104 bombout(("Protocol confusion"));
2105 crReturnV;
e5574168 2106 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2107 c_write_str("Server refused to allocate pty\r\n");
0965bee0 2108 ssh_editing = ssh_echoing = 1;
fef97f43 2109 }
c5e9c988 2110 logevent("Allocated pty");
0965bee0 2111 } else {
2112 ssh_editing = ssh_echoing = 1;
374330e2 2113 }
2114
4ba9b64b 2115 if (cfg.compression) {
2116 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2117 do { crReturnV; } while (!ispkt);
2118 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2119 bombout(("Protocol confusion"));
2120 crReturnV;
2121 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2122 c_write_str("Server refused to compress\r\n");
4ba9b64b 2123 }
2124 logevent("Started compression");
2125 ssh1_compressing = TRUE;
2126 zlib_compress_init();
2127 zlib_decompress_init();
2128 }
2129
6abbf9e3 2130 if (*cfg.remote_cmd)
2131 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
2132 else
2133 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 2134 logevent("Started session");
374330e2 2135
2136 ssh_state = SSH_STATE_SESSION;
2137 if (size_needed)
2138 ssh_size();
3687d221 2139 if (eof_needed)
2140 ssh_special(TS_EOF);
374330e2 2141
0965bee0 2142 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2143 ssh_send_ok = 1;
dacbd0e8 2144 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2145 while (1) {
2146 crReturnV;
2147 if (ispkt) {
e5574168 2148 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2149 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2150 long len = GET_32BIT(pktin.body);
fe50e814 2151 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2152 pktin.body+4, len);
e5574168 2153 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 2154 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2155 logevent("Received disconnect request");
3257deae 2156 crReturnV;
9c964e85 2157 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2158 /* Remote side is trying to open a channel to talk to our
2159 * X-Server. Give them back a local channel number. */
2160 unsigned i;
2161 struct ssh_channel *c, *d;
2162 enum234 e;
2163
2164 logevent("Received X11 connect request");
2165 /* Refuse if X11 forwarding is disabled. */
2166 if (!ssh_X11_fwd_enabled) {
2167 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2168 PKT_INT, GET_32BIT(pktin.body),
2169 PKT_END);
2170 logevent("Rejected X11 connect request");
2171 } else {
9c964e85 2172 c = smalloc(sizeof(struct ssh_channel));
2173
0c6c9a70 2174 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 2175 logevent("opening X11 forward connection failed");
2176 sfree(c);
2177 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2178 PKT_INT, GET_32BIT(pktin.body),
2179 PKT_END);
2180 } else {
2181 logevent("opening X11 forward connection succeeded");
2182 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 2183 if (d->localid > i)
2184 break; /* found a free number */
2185 i = d->localid + 1;
9c964e85 2186 }
2187 c->remoteid = GET_32BIT(pktin.body);
2188 c->localid = i;
2189 c->closes = 0;
783415f8 2190 c->type = CHAN_X11; /* identify channel type */
9c964e85 2191 add234(ssh_channels, c);
2192 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2193 PKT_INT, c->remoteid, PKT_INT, c->localid,
2194 PKT_END);
2195 logevent("Opened X11 forward channel");
2196 }
2197 }
dacbd0e8 2198 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2199 /* Remote side is trying to open a channel to talk to our
2200 * agent. Give them back a local channel number. */
db7d555c 2201 unsigned i;
dacbd0e8 2202 struct ssh_channel *c;
2203 enum234 e;
db7d555c 2204
2205 /* Refuse if agent forwarding is disabled. */
2206 if (!ssh_agentfwd_enabled) {
2207 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2208 PKT_INT, GET_32BIT(pktin.body),
2209 PKT_END);
2210 } else {
2211 i = 1;
2212 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2213 if (c->localid > i)
2214 break; /* found a free number */
2215 i = c->localid + 1;
2216 }
dcbde236 2217 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2218 c->remoteid = GET_32BIT(pktin.body);
2219 c->localid = i;
2220 c->closes = 0;
783415f8 2221 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2222 c->u.a.lensofar = 0;
2223 add234(ssh_channels, c);
2224 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2225 PKT_INT, c->remoteid, PKT_INT, c->localid,
2226 PKT_END);
2227 }
2228 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2229 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 2230 /* Remote side closes a channel. */
d211621f 2231 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 2232 struct ssh_channel *c;
2233 c = find234(ssh_channels, &i, ssh_channelfind);
2234 if (c) {
2235 int closetype;
2236 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2237 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 2238 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 2239 logevent("X11 connection closed");
2240 assert(c->u.x11.s != NULL);
2241 x11_close(c->u.x11.s);
2242 c->u.x11.s = NULL;
2243 }
dacbd0e8 2244 c->closes |= closetype;
2245 if (c->closes == 3) {
2246 del234(ssh_channels, c);
dcbde236 2247 sfree(c);
dacbd0e8 2248 }
2249 }
2250 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2251 /* Data sent down one of our channels. */
2252 int i = GET_32BIT(pktin.body);
2253 int len = GET_32BIT(pktin.body+4);
2254 unsigned char *p = pktin.body+8;
2255 struct ssh_channel *c;
2256 c = find234(ssh_channels, &i, ssh_channelfind);
2257 if (c) {
2258 switch(c->type) {
783415f8 2259 case CHAN_X11:
9c964e85 2260 x11_send(c->u.x11.s, p, len);
2261 break;
783415f8 2262 case CHAN_AGENT:
dacbd0e8 2263 /* Data for an agent message. Buffer it. */
2264 while (len > 0) {
2265 if (c->u.a.lensofar < 4) {
2266 int l = min(4 - c->u.a.lensofar, len);
2267 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2268 p += l; len -= l; c->u.a.lensofar += l;
2269 }
2270 if (c->u.a.lensofar == 4) {
2271 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2272 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2273 memcpy(c->u.a.message, c->u.a.msglen, 4);
2274 }
2275 if (c->u.a.lensofar >= 4 && len > 0) {
2276 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2277 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2278 p += l; len -= l; c->u.a.lensofar += l;
2279 }
2280 if (c->u.a.lensofar == c->u.a.totallen) {
2281 void *reply, *sentreply;
2282 int replylen;
2283 agent_query(c->u.a.message, c->u.a.totallen,
2284 &reply, &replylen);
2285 if (reply)
2286 sentreply = reply;
2287 else {
2288 /* Fake SSH_AGENT_FAILURE. */
2289 sentreply = "\0\0\0\1\5";
2290 replylen = 5;
2291 }
2292 send_packet(SSH1_MSG_CHANNEL_DATA,
2293 PKT_INT, c->remoteid,
2294 PKT_INT, replylen,
2295 PKT_DATA, sentreply, replylen,
2296 PKT_END);
2297 if (reply)
dcbde236 2298 sfree(reply);
2299 sfree(c->u.a.message);
dacbd0e8 2300 c->u.a.lensofar = 0;
2301 }
2302 }
2303 break;
2304 }
2305 }
e5574168 2306 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2307 /* may be from EXEC_SHELL on some servers */
e5574168 2308 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2309 /* may be from EXEC_SHELL on some servers
374330e2 2310 * if no pty is available or in other odd cases. Ignore */
e5574168 2311 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2312 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2313 } else {
8d5de777 2314 bombout(("Strange packet received: type %d", pktin.type));
2315 crReturnV;
374330e2 2316 }
2317 } else {
8df7a775 2318 while (inlen > 0) {
2319 int len = min(inlen, 512);
2320 send_packet(SSH1_CMSG_STDIN_DATA,
2321 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2322 in += len;
2323 inlen -= len;
2324 }
374330e2 2325 }
2326 }
2327
2328 crFinishV;
2329}
2330
2331/*
e5574168 2332 * Utility routine for decoding comma-separated strings in KEXINIT.
2333 */
75cab814 2334static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2335 int needlen = strlen(needle);
2336 while (1) {
2337 /*
2338 * Is it at the start of the string?
2339 */
2340 if (haylen >= needlen && /* haystack is long enough */
2341 !memcmp(needle, haystack, needlen) && /* initial match */
2342 (haylen == needlen || haystack[needlen] == ',')
2343 /* either , or EOS follows */
2344 )
2345 return 1;
2346 /*
2347 * If not, search for the next comma and resume after that.
2348 * If no comma found, terminate.
2349 */
2350 while (haylen > 0 && *haystack != ',')
2351 haylen--, haystack++;
2352 if (haylen == 0)
2353 return 0;
2354 haylen--, haystack++; /* skip over comma itself */
2355 }
2356}
2357
2358/*
d39f364a 2359 * SSH2 key creation method.
2360 */
5e0d7cb8 2361static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
d39f364a 2362 SHA_State s;
2363 /* First 20 bytes. */
2364 SHA_Init(&s);
2365 sha_mpint(&s, K);
2366 SHA_Bytes(&s, H, 20);
2367 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2368 SHA_Bytes(&s, sessid, 20);
d39f364a 2369 SHA_Final(&s, keyspace);
2370 /* Next 20 bytes. */
2371 SHA_Init(&s);
2372 sha_mpint(&s, K);
2373 SHA_Bytes(&s, H, 20);
2374 SHA_Bytes(&s, keyspace, 20);
2375 SHA_Final(&s, keyspace+20);
2376}
2377
2378/*
7cca0d81 2379 * Handle the SSH2 transport layer.
e5574168 2380 */
7cca0d81 2381static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2382{
7bd5a860 2383 static int i, j, len, nbits, pbits;
e5574168 2384 static char *str;
a92dd380 2385 static Bignum p, g, e, f, K;
2386 static int kex_init_value, kex_reply_value;
7591b9ff 2387 static const struct ssh_mac **maclist;
8b2715b2 2388 static int nmacs;
0a3f1d48 2389 static const struct ssh2_cipher *cscipher_tobe = NULL;
2390 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 2391 static const struct ssh_mac *csmac_tobe = NULL;
2392 static const struct ssh_mac *scmac_tobe = NULL;
2393 static const struct ssh_compress *cscomp_tobe = NULL;
2394 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2395 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2396 static int hostkeylen, siglen;
e055a386 2397 static void *hkey; /* actual host key */
e5574168 2398 static unsigned char exchange_hash[20];
d39f364a 2399 static unsigned char keyspace[40];
0a3f1d48 2400 static const struct ssh2_ciphers *preferred_cipher;
4ba9b64b 2401 static const struct ssh_compress *preferred_comp;
0db56f73 2402 static int first_kex;
e5574168 2403
2404 crBegin;
7cca0d81 2405 random_init();
0db56f73 2406 first_kex = 1;
e5574168 2407
5e8358ad 2408 /*
4ba9b64b 2409 * Set up the preferred cipher and compression.
5e8358ad 2410 */
2411 if (cfg.cipher == CIPHER_BLOWFISH) {
0a3f1d48 2412 preferred_cipher = &ssh2_blowfish;
5e8358ad 2413 } else if (cfg.cipher == CIPHER_DES) {
2414 logevent("Single DES not supported in SSH2; using 3DES");
0a3f1d48 2415 preferred_cipher = &ssh2_3des;
5e8358ad 2416 } else if (cfg.cipher == CIPHER_3DES) {
0a3f1d48 2417 preferred_cipher = &ssh2_3des;
2418 } else if (cfg.cipher == CIPHER_AES) {
2419 preferred_cipher = &ssh2_aes;
5e8358ad 2420 } else {
2421 /* Shouldn't happen, but we do want to initialise to _something_. */
0a3f1d48 2422 preferred_cipher = &ssh2_3des;
5e8358ad 2423 }
4ba9b64b 2424 if (cfg.compression)
2425 preferred_comp = &ssh_zlib;
2426 else
2427 preferred_comp = &ssh_comp_none;
5e8358ad 2428
7591b9ff 2429 /*
2430 * Be prepared to work around the buggy MAC problem.
2431 */
7d503c31 2432 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
8b2715b2 2433 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2434 else
8b2715b2 2435 maclist = macs, nmacs = lenof(macs);
7591b9ff 2436
7cca0d81 2437 begin_key_exchange:
e5574168 2438 /*
2439 * Construct and send our key exchange packet.
2440 */
2441 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2442 for (i = 0; i < 16; i++)
2443 ssh2_pkt_addbyte((unsigned char)random_byte());
2444 /* List key exchange algorithms. */
2445 ssh2_pkt_addstring_start();
2446 for (i = 0; i < lenof(kex_algs); i++) {
2447 ssh2_pkt_addstring_str(kex_algs[i]->name);
2448 if (i < lenof(kex_algs)-1)
2449 ssh2_pkt_addstring_str(",");
2450 }
2451 /* List server host key algorithms. */
2452 ssh2_pkt_addstring_start();
2453 for (i = 0; i < lenof(hostkey_algs); i++) {
2454 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2455 if (i < lenof(hostkey_algs)-1)
2456 ssh2_pkt_addstring_str(",");
2457 }
2458 /* List client->server encryption algorithms. */
2459 ssh2_pkt_addstring_start();
729e54b4 2460 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2461 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2462 for (j = 0; j < c->nciphers; j++) {
2463 ssh2_pkt_addstring_str(c->list[j]->name);
2464 if (i < lenof(ciphers) || j < c->nciphers-1)
2465 ssh2_pkt_addstring_str(",");
2466 }
e5574168 2467 }
2468 /* List server->client encryption algorithms. */
2469 ssh2_pkt_addstring_start();
729e54b4 2470 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2471 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2472 for (j = 0; j < c->nciphers; j++) {
2473 ssh2_pkt_addstring_str(c->list[j]->name);
2474 if (i < lenof(ciphers) || j < c->nciphers-1)
2475 ssh2_pkt_addstring_str(",");
2476 }
e5574168 2477 }
2478 /* List client->server MAC algorithms. */
2479 ssh2_pkt_addstring_start();
8b2715b2 2480 for (i = 0; i < nmacs; i++) {
7591b9ff 2481 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2482 if (i < nmacs-1)
e5574168 2483 ssh2_pkt_addstring_str(",");
2484 }
2485 /* List server->client MAC algorithms. */
2486 ssh2_pkt_addstring_start();
8b2715b2 2487 for (i = 0; i < nmacs; i++) {
7591b9ff 2488 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2489 if (i < nmacs-1)
e5574168 2490 ssh2_pkt_addstring_str(",");
2491 }
2492 /* List client->server compression algorithms. */
2493 ssh2_pkt_addstring_start();
4ba9b64b 2494 for (i = 0; i < lenof(compressions)+1; i++) {
2495 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2496 ssh2_pkt_addstring_str(c->name);
2497 if (i < lenof(compressions))
e5574168 2498 ssh2_pkt_addstring_str(",");
2499 }
2500 /* List server->client compression algorithms. */
2501 ssh2_pkt_addstring_start();
4ba9b64b 2502 for (i = 0; i < lenof(compressions)+1; i++) {
2503 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2504 ssh2_pkt_addstring_str(c->name);
2505 if (i < lenof(compressions))
e5574168 2506 ssh2_pkt_addstring_str(",");
2507 }
2508 /* List client->server languages. Empty list. */
2509 ssh2_pkt_addstring_start();
2510 /* List server->client languages. Empty list. */
2511 ssh2_pkt_addstring_start();
2512 /* First KEX packet does _not_ follow, because we're not that brave. */
2513 ssh2_pkt_addbool(FALSE);
2514 /* Reserved. */
2515 ssh2_pkt_adduint32(0);
0db56f73 2516
2517 exhash = exhashbase;
e5574168 2518 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2519
e5574168 2520 ssh2_pkt_send();
2521
2522 if (!ispkt) crWaitUntil(ispkt);
2523 sha_string(&exhash, pktin.data+5, pktin.length-5);
2524
2525 /*
2526 * Now examine the other side's KEXINIT to see what we're up
2527 * to.
2528 */
7cca0d81 2529 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2530 bombout(("expected key exchange packet from server"));
2531 crReturn(0);
7cca0d81 2532 }
e5574168 2533 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2534 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2535 pktin.savedpos += 16; /* skip garbage cookie */
2536 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2537 for (i = 0; i < lenof(kex_algs); i++) {
2538 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2539 kex = kex_algs[i];
2540 break;
2541 }
2542 }
2543 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2544 for (i = 0; i < lenof(hostkey_algs); i++) {
2545 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2546 hostkey = hostkey_algs[i];
2547 break;
2548 }
2549 }
2550 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2551 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2552 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2553 for (j = 0; j < c->nciphers; j++) {
2554 if (in_commasep_string(c->list[j]->name, str, len)) {
2555 cscipher_tobe = c->list[j];
2556 break;
2557 }
e5574168 2558 }
0a3f1d48 2559 if (cscipher_tobe)
2560 break;
e5574168 2561 }
2562 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2563 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2564 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2565 for (j = 0; j < c->nciphers; j++) {
2566 if (in_commasep_string(c->list[j]->name, str, len)) {
2567 sccipher_tobe = c->list[j];
2568 break;
2569 }
e5574168 2570 }
0a3f1d48 2571 if (sccipher_tobe)
2572 break;
e5574168 2573 }
2574 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2575 for (i = 0; i < nmacs; i++) {
7591b9ff 2576 if (in_commasep_string(maclist[i]->name, str, len)) {
2577 csmac_tobe = maclist[i];
e5574168 2578 break;
2579 }
2580 }
2581 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2582 for (i = 0; i < nmacs; i++) {
7591b9ff 2583 if (in_commasep_string(maclist[i]->name, str, len)) {
2584 scmac_tobe = maclist[i];
e5574168 2585 break;
2586 }
2587 }
2588 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2589 for (i = 0; i < lenof(compressions)+1; i++) {
2590 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2591 if (in_commasep_string(c->name, str, len)) {
2592 cscomp_tobe = c;
e5574168 2593 break;
2594 }
2595 }
2596 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2597 for (i = 0; i < lenof(compressions)+1; i++) {
2598 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2599 if (in_commasep_string(c->name, str, len)) {
2600 sccomp_tobe = c;
e5574168 2601 break;
2602 }
2603 }
e5574168 2604
2605 /*
7bd5a860 2606 * Work out the number of bits of key we will need from the key
2607 * exchange. We start with the maximum key length of either
2608 * cipher...
2609 */
2610 {
2611 int csbits, scbits;
2612
2613 csbits = cscipher_tobe->keylen;
2614 scbits = sccipher_tobe->keylen;
2615 nbits = (csbits > scbits ? csbits : scbits);
2616 }
2617 /* The keys only have 160-bit entropy, since they're based on
2618 * a SHA-1 hash. So cap the key size at 160 bits. */
2619 if (nbits > 160) nbits = 160;
2620
2621 /*
a92dd380 2622 * If we're doing Diffie-Hellman group exchange, start by
2623 * requesting a group.
e5574168 2624 */
a92dd380 2625 if (kex == &ssh_diffiehellman_gex) {
a92dd380 2626 logevent("Doing Diffie-Hellman group exchange");
2627 /*
7bd5a860 2628 * Work out how big a DH group we will need to allow that
2629 * much data.
2630 */
2631 pbits = 512 << ((nbits-1) / 64);
a92dd380 2632 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
7bd5a860 2633 ssh2_pkt_adduint32(pbits);
a92dd380 2634 ssh2_pkt_send();
2635
2636 crWaitUntil(ispkt);
2637 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2638 bombout(("expected key exchange group packet from server"));
2639 crReturn(0);
2640 }
2641 p = ssh2_pkt_getmp();
2642 g = ssh2_pkt_getmp();
2643 dh_setup_group(p, g);
2644 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2645 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2646 } else {
2647 dh_setup_group1();
2648 kex_init_value = SSH2_MSG_KEXDH_INIT;
2649 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 2650 }
e5574168 2651
a92dd380 2652 logevent("Doing Diffie-Hellman key exchange");
e5574168 2653 /*
a92dd380 2654 * Now generate and send e for Diffie-Hellman.
e5574168 2655 */
7bd5a860 2656 e = dh_create_e(nbits*2);
a92dd380 2657 ssh2_pkt_init(kex_init_value);
e5574168 2658 ssh2_pkt_addmp(e);
2659 ssh2_pkt_send();
2660
2661 crWaitUntil(ispkt);
a92dd380 2662 if (pktin.type != kex_reply_value) {
2663 bombout(("expected key exchange reply packet from server"));
8d5de777 2664 crReturn(0);
7cca0d81 2665 }
e5574168 2666 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2667 f = ssh2_pkt_getmp();
e5574168 2668 ssh2_pkt_getstring(&sigdata, &siglen);
2669
2670 K = dh_find_K(f);
e5574168 2671
2672 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 2673 if (kex == &ssh_diffiehellman_gex) {
7bd5a860 2674 sha_uint32(&exhash, pbits);
a92dd380 2675 sha_mpint(&exhash, p);
2676 sha_mpint(&exhash, g);
2677 }
e5574168 2678 sha_mpint(&exhash, e);
2679 sha_mpint(&exhash, f);
2680 sha_mpint(&exhash, K);
2681 SHA_Final(&exhash, exchange_hash);
2682
3709bfe9 2683 dh_cleanup();
2684
7cca0d81 2685#if 0
e5574168 2686 debug(("Exchange hash is:\r\n"));
2687 for (i = 0; i < 20; i++)
2688 debug((" %02x", exchange_hash[i]));
2689 debug(("\r\n"));
7cca0d81 2690#endif
2691
e055a386 2692 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2693 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2694 bombout(("Server failed host key check"));
2695 crReturn(0);
2696 }
e5574168 2697
2698 /*
7cca0d81 2699 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2700 */
7cca0d81 2701 crWaitUntil(ispkt);
8d5de777 2702 if (pktin.type != SSH2_MSG_NEWKEYS) {
2703 bombout(("expected new-keys packet from server"));
2704 crReturn(0);
2705 }
d39f364a 2706
2707 /*
7cca0d81 2708 * Authenticate remote host: verify host key. (We've already
2709 * checked the signature of the exchange hash.)
e5574168 2710 */
e055a386 2711 keystr = hostkey->fmtkey(hkey);
2712 fingerprint = hostkey->fingerprint(hkey);
d4857987 2713 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2714 keystr, fingerprint);
a92dd380 2715 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 2716 logevent("Host key fingerprint is:");
2717 logevent(fingerprint);
2718 }
dcbde236 2719 sfree(fingerprint);
2720 sfree(keystr);
e055a386 2721 hostkey->freekey(hkey);
d39f364a 2722
2723 /*
7cca0d81 2724 * Send SSH2_MSG_NEWKEYS.
d39f364a 2725 */
2726 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2727 ssh2_pkt_send();
d39f364a 2728
2729 /*
2730 * Create and initialise session keys.
2731 */
2732 cscipher = cscipher_tobe;
2733 sccipher = sccipher_tobe;
2734 csmac = csmac_tobe;
2735 scmac = scmac_tobe;
2736 cscomp = cscomp_tobe;
2737 sccomp = sccomp_tobe;
4ba9b64b 2738 cscomp->compress_init();
2739 sccomp->decompress_init();
d39f364a 2740 /*
5e0d7cb8 2741 * Set IVs after keys. Here we use the exchange hash from the
2742 * _first_ key exchange.
d39f364a 2743 */
5e0d7cb8 2744 if (first_kex)
65a22376 2745 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2746 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 2747 cscipher->setcskey(keyspace);
65a22376 2748 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 2749 sccipher->setsckey(keyspace);
65a22376 2750 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 2751 cscipher->setcsiv(keyspace);
65a22376 2752 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 2753 sccipher->setsciv(keyspace);
65a22376 2754 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 2755 csmac->setcskey(keyspace);
65a22376 2756 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 2757 scmac->setsckey(keyspace);
d39f364a 2758
033b4cef 2759 /*
0db56f73 2760 * If this is the first key exchange phase, we must pass the
2761 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2762 * wants to see it but because it will need time to initialise
2763 * itself before it sees an actual packet. In subsequent key
2764 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2765 * it would only confuse the layer above.
2766 */
2767 if (!first_kex) {
2768 crReturn(0);
2769 }
2770 first_kex = 0;
2771
2772 /*
7cca0d81 2773 * Now we're encrypting. Begin returning 1 to the protocol main
2774 * function so that other things can run on top of the
2775 * transport. If we ever see a KEXINIT, we must go back to the
2776 * start.
033b4cef 2777 */
e96adf72 2778 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
7cca0d81 2779 crReturn(1);
e96adf72 2780 }
5e0d7cb8 2781 logevent("Server initiated key re-exchange");
7cca0d81 2782 goto begin_key_exchange;
e5574168 2783
2784 crFinish(1);
2785}
2786
7cca0d81 2787/*
783415f8 2788 * Add data to an SSH2 channel output buffer.
2789 */
2790static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2791 if (c->v2.outbufsize <
2792 c->v2.outbuflen + len) {
2793 c->v2.outbufsize =
2794 c->v2.outbuflen + len + 1024;
2795 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2796 c->v2.outbufsize);
2797 }
2798 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2799 buf, len);
2800 c->v2.outbuflen += len;
2801}
2802
2803/*
2804 * Attempt to send data on an SSH2 channel.
2805 */
2806static void ssh2_try_send(struct ssh_channel *c) {
2807 while (c->v2.remwindow > 0 &&
2808 c->v2.outbuflen > 0) {
2809 unsigned len = c->v2.remwindow;
2810 if (len > c->v2.outbuflen)
2811 len = c->v2.outbuflen;
2812 if (len > c->v2.remmaxpkt)
2813 len = c->v2.remmaxpkt;
2814 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2815 ssh2_pkt_adduint32(c->remoteid);
2816 ssh2_pkt_addstring_start();
2817 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2818 ssh2_pkt_send();
2819 c->v2.outbuflen -= len;
2820 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2821 c->v2.outbuflen);
2822 c->v2.remwindow -= len;
2823 }
2824}
2825
2826/*
7cca0d81 2827 * Handle the SSH2 userauth and connection layers.
2828 */
2829static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2830{
7cca0d81 2831 static unsigned long remote_winsize;
2832 static unsigned long remote_maxpkt;
65a22376 2833 static enum {
2834 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2835 } method;
1408a877 2836 static enum {
2837 AUTH_TYPE_NONE,
2838 AUTH_TYPE_PUBLICKEY,
2839 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2840 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2841 AUTH_TYPE_PASSWORD
2842 } type;
1983e559 2843 static int gotit, need_pw, can_pubkey, can_passwd;
2844 static int tried_pubkey_config, tried_agent;
1408a877 2845 static int we_are_in;
65a22376 2846 static char username[100];
2847 static char pwprompt[200];
2848 static char password[100];
7cca0d81 2849
e5574168 2850 crBegin;
2851
7cca0d81 2852 /*
2853 * Request userauth protocol, and await a response to it.
2854 */
2855 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2856 ssh2_pkt_addstring("ssh-userauth");
2857 ssh2_pkt_send();
2858 crWaitUntilV(ispkt);
8d5de777 2859 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2860 bombout(("Server refused user authentication protocol"));
2861 crReturnV;
2862 }
7cca0d81 2863
2864 /*
1408a877 2865 * We repeat this whole loop, including the username prompt,
2866 * until we manage a successful authentication. If the user
2867 * types the wrong _password_, they are sent back to the
2868 * beginning to try another username. (If they specify a
2869 * username in the config, they are never asked, even if they
2870 * do give a wrong password.)
2871 *
2872 * I think this best serves the needs of
2873 *
2874 * - the people who have no configuration, no keys, and just
2875 * want to try repeated (username,password) pairs until they
2876 * type both correctly
2877 *
2878 * - people who have keys and configuration but occasionally
2879 * need to fall back to passwords
2880 *
2881 * - people with a key held in Pageant, who might not have
2882 * logged in to a particular machine before; so they want to
2883 * type a username, and then _either_ their key will be
2884 * accepted, _or_ they will type a password. If they mistype
2885 * the username they will want to be able to get back and
2886 * retype it!
7cca0d81 2887 */
1408a877 2888 do {
2889 static int pos;
7cca0d81 2890 static char c;
e5574168 2891
1408a877 2892 /*
2893 * Get a username.
2894 */
2895 pos = 0;
67779be7 2896 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 2897 if (ssh_get_line) {
2898 if (!ssh_get_line("login as: ",
2899 username, sizeof(username), FALSE)) {
2900 /*
2901 * get_line failed to get a username.
2902 * Terminate.
2903 */
2904 logevent("No username provided. Abandoning session.");
2905 ssh_state = SSH_STATE_CLOSED;
dae2b91f 2906 crReturnV;
fa17a66e 2907 }
2908 } else {
2909 c_write_str("login as: ");
2910 ssh_send_ok = 1;
2911 while (pos >= 0) {
2912 crWaitUntilV(!ispkt);
2913 while (inlen--) switch (c = *in++) {
2914 case 10: case 13:
2915 username[pos] = 0;
2916 pos = -1;
2917 break;
2918 case 8: case 127:
2919 if (pos > 0) {
2920 c_write_str("\b \b");
2921 pos--;
2922 }
2923 break;
2924 case 21: case 27:
2925 while (pos > 0) {
2926 c_write_str("\b \b");
2927 pos--;
2928 }
2929 break;
2930 case 3: case 4:
2931 random_save_seed();
2932 exit(0);
2933 break;
2934 default:
2935 if (((c >= ' ' && c <= '~') ||
2936 ((unsigned char)c >= 160)) && pos < 40) {
2937 username[pos++] = c;
2938 c_write(&c, 1);
2939 }
2940 break;
2941 }
2942 }
2943 }
1408a877 2944 c_write_str("\r\n");
7cca0d81 2945 username[strcspn(username, "\n\r")] = '\0';
2946 } else {
2947 char stuff[200];
2948 strncpy(username, cfg.username, 99);
2949 username[99] = '\0';
65a22376 2950 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2951 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 2952 c_write_str(stuff);
7cca0d81 2953 }
2954 }
2955
65a22376 2956 /*
1408a877 2957 * Send an authentication request using method "none": (a)
2958 * just in case it succeeds, and (b) so that we know what
2959 * authentication methods we can usefully try next.
65a22376 2960 */
1408a877 2961 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2962 ssh2_pkt_addstring(username);
2963 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2964 ssh2_pkt_addstring("none"); /* method */
2965 ssh2_pkt_send();
2966 type = AUTH_TYPE_NONE;
2967 gotit = FALSE;
2968 we_are_in = FALSE;
7cca0d81 2969
1408a877 2970 tried_pubkey_config = FALSE;
1983e559 2971 tried_agent = FALSE;
65a22376 2972
1408a877 2973 while (1) {
2974 /*
2975 * Wait for the result of the last authentication request.
2976 */
2977 if (!gotit)
2978 crWaitUntilV(ispkt);
2979 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
a209e957 2980 char *banner;
2981 int size;
2982 ssh2_pkt_getstring(&banner, &size);
2983 if (banner)
2984 c_write_untrusted(banner, size);
1408a877 2985 crWaitUntilV(ispkt);
2986 }
2987 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2988 logevent("Access granted");
2989 we_are_in = TRUE;
2990 break;
2991 }
65a22376 2992
1408a877 2993 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2994 bombout(("Strange packet received during authentication: type %d",
2995 pktin.type));
65a22376 2996 }
2997
1408a877 2998 gotit = FALSE;
65a22376 2999
1408a877 3000 /*
3001 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3002 * we can look at the string in it and know what we can
3003 * helpfully try next.
3004 */
3005 {
3006 char *methods;
3007 int methlen;
3008 ssh2_pkt_getstring(&methods, &methlen);
3009 if (!ssh2_pkt_getbool()) {
3010 /*
3011 * We have received an unequivocal Access
3012 * Denied. This can translate to a variety of
3013 * messages:
3014 *
3015 * - if we'd just tried "none" authentication,
3016 * it's not worth printing anything at all
3017 *
3018 * - if we'd just tried a public key _offer_,
3019 * the message should be "Server refused our
3020 * key" (or no message at all if the key
3021 * came from Pageant)
3022 *
3023 * - if we'd just tried anything else, the
3024 * message really should be "Access denied".
3025 *
3026 * Additionally, if we'd just tried password
3027 * authentication, we should break out of this
3028 * whole loop so as to go back to the username
3029 * prompt.
3030 */
3031 if (type == AUTH_TYPE_NONE) {
3032 /* do nothing */
3033 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3034 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3035 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3036 c_write_str("Server refused our key\r\n");
3037 logevent("Server refused public key");
3038 } else {
3039 c_write_str("Access denied\r\n");
3040 logevent("Access denied");
3041 if (type == AUTH_TYPE_PASSWORD) {
3042 we_are_in = FALSE;
3043 break;
3044 }
3045 }
3046 } else {
3047 c_write_str("Further authentication required\r\n");
3048 logevent("Further authentication required");
3049 }
65a22376 3050
1408a877 3051 can_pubkey = in_commasep_string("publickey", methods, methlen);
3052 can_passwd = in_commasep_string("password", methods, methlen);
3053 }
65a22376 3054
1408a877 3055 method = 0;
65a22376 3056
1983e559 3057 if (!method && can_pubkey && agent_exists && !tried_agent) {
3058 /*
3059 * Attempt public-key authentication using Pageant.
3060 */
3061 static unsigned char request[5], *response, *p;
3062 static int responselen;
3063 static int i, nkeys;
3064 static int authed = FALSE;
3065 void *r;
3066
3067 tried_agent = TRUE;
3068
3069 logevent("Pageant is running. Requesting keys.");
3070
3071 /* Request the keys held by the agent. */
3072 PUT_32BIT(request, 1);
3073 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3074 agent_query(request, 5, &r, &responselen);
3075 response = (unsigned char *)r;
95797139 3076 if (response && responselen >= 5 &&
3077 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3078 p = response + 5;
3079 nkeys = GET_32BIT(p); p += 4;
6328ea7a 3080 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
1983e559 3081 logevent(buf); }
3082 for (i = 0; i < nkeys; i++) {
3083 static char *pkblob, *alg, *commentp;
3084 static int pklen, alglen, commentlen;
3085 static int siglen, retlen, len;
3086 static char *q, *agentreq, *ret;
3087
3088 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3089 logevent(buf); }
3090 pklen = GET_32BIT(p); p += 4;
3091 pkblob = p; p += pklen;
3092 alglen = GET_32BIT(pkblob);
3093 alg = pkblob + 4;
3094 commentlen = GET_32BIT(p); p += 4;
3095 commentp = p; p += commentlen;
3096 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3097 ssh2_pkt_addstring(username);
3098 ssh2_pkt_addstring("ssh-connection");/* service requested */
3099 ssh2_pkt_addstring("publickey");/* method */
3100 ssh2_pkt_addbool(FALSE); /* no signature included */
3101 ssh2_pkt_addstring_start();
3102 ssh2_pkt_addstring_data(alg, alglen);
3103 ssh2_pkt_addstring_start();
3104 ssh2_pkt_addstring_data(pkblob, pklen);
3105 ssh2_pkt_send();
3106
3107 crWaitUntilV(ispkt);
3108 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3109 logevent("Key refused");
3110 continue;
3111 }
3112
3113 c_write_str("Authenticating with public key \"");
3114 c_write(commentp, commentlen);
3115 c_write_str("\" from agent\r\n");
3116
3117 /*
3118 * Server is willing to accept the key.
3119 * Construct a SIGN_REQUEST.
3120 */
3121 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3122 ssh2_pkt_addstring(username);
3123 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3124 ssh2_pkt_addstring("publickey"); /* method */
3125 ssh2_pkt_addbool(TRUE);
3126 ssh2_pkt_addstring_start();
3127 ssh2_pkt_addstring_data(alg, alglen);
3128 ssh2_pkt_addstring_start();
3129 ssh2_pkt_addstring_data(pkblob, pklen);
3130
3131 siglen = pktout.length - 5 + 4 + 20;
3132 len = 1; /* message type */
3133 len += 4 + pklen; /* key blob */
3134 len += 4 + siglen; /* data to sign */
3135 len += 4; /* flags */
3136 agentreq = smalloc(4 + len);
3137 PUT_32BIT(agentreq, len);
3138 q = agentreq + 4;
3139 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3140 PUT_32BIT(q, pklen); q += 4;
3141 memcpy(q, pkblob, pklen); q += pklen;
3142 PUT_32BIT(q, siglen); q += 4;
3143 /* Now the data to be signed... */
3144 PUT_32BIT(q, 20); q += 4;
3145 memcpy(q, ssh2_session_id, 20); q += 20;
3146 memcpy(q, pktout.data+5, pktout.length-5);
3147 q += pktout.length-5;
3148 /* And finally the (zero) flags word. */
3149 PUT_32BIT(q, 0);
3150 agent_query(agentreq, len+4, &ret, &retlen);
3151 sfree(agentreq);
3152 if (ret) {
3153 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3154 logevent("Sending Pageant's response");
3155 ssh2_pkt_addstring_start();
3156 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3157 ssh2_pkt_send();
3158 authed = TRUE;
3159 break;
3160 } else {
3161 logevent("Pageant failed to answer challenge");
3162 sfree(ret);
3163 }
3164 }
3165 }
3166 if (authed)
3167 continue;
3168 }
3169 }
3170
1408a877 3171 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3172 unsigned char *pub_blob;
3173 char *algorithm, *comment;
3174 int pub_blob_len;
65a22376 3175
1408a877 3176 tried_pubkey_config = TRUE;
65a22376 3177
65a22376 3178 /*
1408a877 3179 * Try the public key supplied in the configuration.
3180 *
3181 * First, offer the public blob to see if the server is
3182 * willing to accept it.
65a22376 3183 */
1408a877 3184 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3185 &pub_blob_len);
3186 if (pub_blob) {
3187 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3188 ssh2_pkt_addstring(username);
3189 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3190 ssh2_pkt_addstring("publickey");/* method */
3191 ssh2_pkt_addbool(FALSE); /* no signature included */
3192 ssh2_pkt_addstring(algorithm);
3193 ssh2_pkt_addstring_start();
3194 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3195 ssh2_pkt_send();
3196 logevent("Offered public key"); /* FIXME */
3197
3198 crWaitUntilV(ispkt);
3199 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3200 gotit = TRUE;
3201 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3202 continue; /* key refused; give up on it */
3203 }
65a22376 3204
1408a877 3205 logevent("Offer of public key accepted");
65a22376 3206 /*
1408a877 3207 * Actually attempt a serious authentication using
3208 * the key.
65a22376 3209 */
1408a877 3210 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3211 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3212 need_pw = TRUE;
3213 } else {
3214 need_pw = FALSE;
3215 }
3216 c_write_str("Authenticating with public key \"");
3217 c_write_str(comment);
3218 c_write_str("\"\r\n");
3219 method = AUTH_PUBLICKEY_FILE;
65a22376 3220 }
1408a877 3221 }
3222
3223 if (!method && can_passwd) {
3224 method = AUTH_PASSWORD;
3225 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3226 need_pw = TRUE;
3227 }
3228
3229 if (need_pw) {
fa17a66e 3230 if (ssh_get_line) {
3231 if (!ssh_get_line(pwprompt, password,
3232 sizeof(password), TRUE)) {
1408a877 3233 /*
fa17a66e 3234 * get_line failed to get a password (for
3235 * example because one was supplied on the
3236 * command line which has already failed to
3237 * work). Terminate.
1408a877 3238 */
3239 logevent("No more passwords to try");
3240 ssh_state = SSH_STATE_CLOSED;
3241 crReturnV;
3242 }
3243 } else {
3244 static int pos = 0;
3245 static char c;
3246
3247 c_write_str(pwprompt);
3248 ssh_send_ok = 1;
3249
3250 pos = 0;
3251 while (pos >= 0) {
3252 crWaitUntilV(!ispkt);
3253 while (inlen--) switch (c = *in++) {
3254 case 10: case 13:
3255 password[pos] = 0;
3256 pos = -1;
3257 break;
3258 case 8: case 127:
3259 if (pos > 0)
3260 pos--;
3261 break;
3262 case 21: case 27:
3263 pos = 0;
3264 break;
3265 case 3: case 4:
3266 random_save_seed();
3267 exit(0);
3268 break;
3269 default:
3270 if (((c >= ' ' && c <= '~') ||
3271 ((unsigned char)c >= 160)) && pos < 40)
3272 password[pos++] = c;
3273 break;
3274 }
65a22376 3275 }
1408a877 3276 c_write_str("\r\n");
65a22376 3277 }
65a22376 3278 }
65a22376 3279
1408a877 3280 if (method == AUTH_PUBLICKEY_FILE) {
3281 /*
3282 * We have our passphrase. Now try the actual authentication.
3283 */
3284 struct ssh2_userkey *key;
65a22376 3285
1408a877 3286 key = ssh2_load_userkey(cfg.keyfile, password);
3287 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3288 if (key == SSH2_WRONG_PASSPHRASE) {
3289 c_write_str("Wrong passphrase\r\n");
3290 tried_pubkey_config = FALSE;
3291 } else {
3292 c_write_str("Unable to load private key\r\n");
3293 tried_pubkey_config = TRUE;
3294 }
3295 /* Send a spurious AUTH_NONE to return to the top. */
3296 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3297 ssh2_pkt_addstring(username);
3298 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3299 ssh2_pkt_addstring("none"); /* method */
3300 ssh2_pkt_send();
3301 type = AUTH_TYPE_NONE;
3302 } else {
3303 unsigned char *blob, *sigdata;
3304 int blob_len, sigdata_len;
65a22376 3305
1408a877 3306 /*
3307 * We have loaded the private key and the server
3308 * has announced that it's willing to accept it.
3309 * Hallelujah. Generate a signature and send it.
3310 */
3311 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3312 ssh2_pkt_addstring(username);
3313 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3314 ssh2_pkt_addstring("publickey"); /* method */
3315 ssh2_pkt_addbool(TRUE);
3316 ssh2_pkt_addstring(key->alg->name);
3317 blob = key->alg->public_blob(key->data, &blob_len);
3318 ssh2_pkt_addstring_start();
3319 ssh2_pkt_addstring_data(blob, blob_len);
3320 sfree(blob);
3321
3322 /*
3323 * The data to be signed is:
3324 *
3325 * string session-id
3326 *
3327 * followed by everything so far placed in the
3328 * outgoing packet.
3329 */
3330 sigdata_len = pktout.length - 5 + 4 + 20;
3331 sigdata = smalloc(sigdata_len);
3332 PUT_32BIT(sigdata, 20);
3333 memcpy(sigdata+4, ssh2_session_id, 20);
3334 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3335 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3336 ssh2_pkt_addstring_start();
3337 ssh2_pkt_addstring_data(blob, blob_len);
3338 sfree(blob);
3339 sfree(sigdata);
3340
3341 ssh2_pkt_send();
3342 type = AUTH_TYPE_PUBLICKEY;
3343 }
3344 } else if (method == AUTH_PASSWORD) {
65a22376 3345 /*
1408a877 3346 * We send the password packet lumped tightly together with
3347 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3348 * string long enough to make the total length of the two
3349 * packets constant. This should ensure that a passive
3350 * listener doing traffic analyis can't work out the length
3351 * of the password.
3352 *
3353 * For this to work, we need an assumption about the
3354 * maximum length of the password packet. I think 256 is
3355 * pretty conservative. Anyone using a password longer than
3356 * that probably doesn't have much to worry about from
3357 * people who find out how long their password is!
65a22376 3358 */
3359 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3360 ssh2_pkt_addstring(username);
3361 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3362 ssh2_pkt_addstring("password");
3363 ssh2_pkt_addbool(FALSE);
3364 ssh2_pkt_addstring(password);
3365 ssh2_pkt_defer();
65a22376 3366 /*
1408a877 3367 * We'll include a string that's an exact multiple of the
3368 * cipher block size. If the cipher is NULL for some
3369 * reason, we don't do this trick at all because we gain
3370 * nothing by it.
65a22376 3371 */
6e9e9520 3372 if (cscipher) {
3373 int stringlen, i;
3374
3375 stringlen = (256 - deferred_len);
3376 stringlen += cscipher->blksize - 1;
3377 stringlen -= (stringlen % cscipher->blksize);
3378 if (cscomp) {
3379 /*
3380 * Temporarily disable actual compression,
3381 * so we can guarantee to get this string
3382 * exactly the length we want it. The
3383 * compression-disabling routine should
3384 * return an integer indicating how many
3385 * bytes we should adjust our string length
3386 * by.
3387 */
3388 stringlen -= cscomp->disable_compression();
3389 }
1408a877 3390 ssh2_pkt_init(SSH2_MSG_IGNORE);
3391 ssh2_pkt_addstring_start();
6e9e9520 3392 for (i = 0; i < stringlen; i++) {
3393 char c = (char)random_byte();
3394 ssh2_pkt_addstring_data(&c, 1);
65a22376 3395 }
1408a877 3396 ssh2_pkt_defer();
65a22376 3397 }
39065bed 3398 ssh_pkt_defersend();
0d43337a 3399 logevent("Sent password");
1408a877 3400 type = AUTH_TYPE_PASSWORD;
3401 } else {
3402 c_write_str("No supported authentication methods left to try!\r\n");
3403 logevent("No supported authentications offered. Disconnecting");
3404 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3405 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3406 ssh2_pkt_addstring("No supported authentication methods available");
3407 ssh2_pkt_addstring("en"); /* language tag */
3408 ssh2_pkt_send();
3409 ssh_state = SSH_STATE_CLOSED;
3410 crReturnV;
65a22376 3411 }
65a22376 3412 }
1408a877 3413 } while (!we_are_in);
7cca0d81 3414
3415 /*
3416 * Now we're authenticated for the connection protocol. The
3417 * connection protocol will automatically have started at this
3418 * point; there's no need to send SERVICE_REQUEST.
3419 */
3420
3421 /*
3422 * So now create a channel with a session in it.
3423 */
dcbde236 3424 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 3425 mainchan->localid = 100; /* as good as any */
7cca0d81 3426 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3427 ssh2_pkt_addstring("session");
d211621f 3428 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 3429 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 3430 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 3431 ssh2_pkt_send();
3432 crWaitUntilV(ispkt);
3433 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 3434 bombout(("Server refused to open a session"));
3435 crReturnV;
7cca0d81 3436 /* FIXME: error data comes back in FAILURE packet */
3437 }
d211621f 3438 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 3439 bombout(("Server's channel confirmation cited wrong channel"));
3440 crReturnV;
7cca0d81 3441 }
d211621f 3442 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 3443 mainchan->type = CHAN_MAINSESSION;
3444 mainchan->closes = 0;
3445 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3446 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3447 mainchan->v2.outbuffer = NULL;
3448 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3449 ssh_channels = newtree234(ssh_channelcmp);
3450 add234(ssh_channels, mainchan);
7cca0d81 3451 logevent("Opened channel for session");
3452
3453 /*
783415f8 3454 * Potentially enable X11 forwarding.
3455 */
3456 if (cfg.x11_forward) {
3457 char proto[20], data[64];
3458 logevent("Requesting X11 forwarding");
3459 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3460 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3461 ssh2_pkt_adduint32(mainchan->remoteid);
3462 ssh2_pkt_addstring("x11-req");
3463 ssh2_pkt_addbool(1); /* want reply */
3464 ssh2_pkt_addbool(0); /* many connections */
3465 ssh2_pkt_addstring(proto);
3466 ssh2_pkt_addstring(data);
3467 ssh2_pkt_adduint32(0); /* screen number */
3468 ssh2_pkt_send();
3469
3470 do {
3471 crWaitUntilV(ispkt);
3472 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3473 unsigned i = ssh2_pkt_getuint32();
3474 struct ssh_channel *c;
3475 c = find234(ssh_channels, &i, ssh_channelfind);
3476 if (!c)
3477 continue; /* nonexistent channel */
3478 c->v2.remwindow += ssh2_pkt_getuint32();
3479 }
3480 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3481
3482 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3483 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3484 bombout(("Server got confused by X11 forwarding request"));
3485 crReturnV;
3486 }
3487 logevent("X11 forwarding refused");
3488 } else {
3489 logevent("X11 forwarding enabled");
3490 ssh_X11_fwd_enabled = TRUE;
3491 }
3492 }
3493
3494 /*
36c2a3e9 3495 * Potentially enable agent forwarding.
3496 */
3497 if (cfg.agentfwd && agent_exists()) {
36c2a3e9 3498 logevent("Requesting OpenSSH-style agent forwarding");
36c2a3e9 3499 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3500 ssh2_pkt_adduint32(mainchan->remoteid);
3501 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3502 ssh2_pkt_addbool(1); /* want reply */
3503 ssh2_pkt_send();
3504
3505 do {
3506 crWaitUntilV(ispkt);
3507 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3508 unsigned i = ssh2_pkt_getuint32();
3509 struct ssh_channel *c;
3510 c = find234(ssh_channels, &i, ssh_channelfind);
3511 if (!c)
3512 continue; /* nonexistent channel */
3513 c->v2.remwindow += ssh2_pkt_getuint32();
3514 }
3515 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3516
3517 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3518 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3519 bombout(("Server got confused by agent forwarding request"));
3520 crReturnV;
3521 }
3522 logevent("Agent forwarding refused");
3523 } else {
3524 logevent("Agent forwarding enabled");
3525 ssh_agentfwd_enabled = TRUE;
3526 }
3527 }
3528
3529 /*
7cca0d81 3530 * Now allocate a pty for the session.
3531 */
67779be7 3532 if (!cfg.nopty) {
3533 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3534 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3535 ssh2_pkt_addstring("pty-req");
3536 ssh2_pkt_addbool(1); /* want reply */
3537 ssh2_pkt_addstring(cfg.termtype);
3538 ssh2_pkt_adduint32(cols);
3539 ssh2_pkt_adduint32(rows);
3540 ssh2_pkt_adduint32(0); /* pixel width */
3541 ssh2_pkt_adduint32(0); /* pixel height */
3542 ssh2_pkt_addstring_start();
3543 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3544 ssh2_pkt_send();
6e48c3fe 3545 ssh_state = SSH_STATE_INTERMED;
7cca0d81 3546
67779be7 3547 do {
3548 crWaitUntilV(ispkt);
3549 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3550 unsigned i = ssh2_pkt_getuint32();
3551 struct ssh_channel *c;
3552 c = find234(ssh_channels, &i, ssh_channelfind);
3553 if (!c)
3554 continue; /* nonexistent channel */
3555 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 3556 }
3557 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 3558
67779be7 3559 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3560 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3561 bombout(("Server got confused by pty request"));
3562 crReturnV;
67779be7 3563 }
1408a877 3564 c_write_str("Server refused to allocate pty\r\n");
0965bee0 3565 ssh_editing = ssh_echoing = 1;
67779be7 3566 } else {
3567 logevent("Allocated pty");
7cca0d81 3568 }
0965bee0 3569 } else {
3570 ssh_editing = ssh_echoing = 1;
7cca0d81 3571 }
3572
3573 /*
67779be7 3574 * Start a shell or a remote command.
7cca0d81 3575 */
3576 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 3577 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4a8fc3c4 3578 if (cfg.ssh_subsys) {
3579 ssh2_pkt_addstring("subsystem");
3580 ssh2_pkt_addbool(1); /* want reply */
3581 ssh2_pkt_addstring(cfg.remote_cmd);
3582 } else if (*cfg.remote_cmd) {
67779be7 3583 ssh2_pkt_addstring("exec");
3584 ssh2_pkt_addbool(1); /* want reply */
3585 ssh2_pkt_addstring(cfg.remote_cmd);
3586 } else {
3587 ssh2_pkt_addstring("shell");
3588 ssh2_pkt_addbool(1); /* want reply */
3589 }
7cca0d81 3590 ssh2_pkt_send();
d211621f 3591 do {
7cca0d81 3592 crWaitUntilV(ispkt);
d211621f 3593 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3594 unsigned i = ssh2_pkt_getuint32();
3595 struct ssh_channel *c;
3596 c = find234(ssh_channels, &i, ssh_channelfind);
3597 if (!c)
3598 continue; /* nonexistent channel */
3599 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3600 }
7cca0d81 3601 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3602 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3603 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3604 bombout(("Server got confused by shell/command request"));
3605 crReturnV;
7cca0d81 3606 }
8d5de777 3607 bombout(("Server refused to start a shell/command"));
3608 crReturnV;
7cca0d81 3609 } else {
8d5de777 3610 logevent("Started a shell/command");
7cca0d81 3611 }
3612
6e48c3fe 3613 ssh_state = SSH_STATE_SESSION;
3614 if (size_needed)
3615 ssh_size();
3687d221 3616 if (eof_needed)
3617 ssh_special(TS_EOF);
6e48c3fe 3618
7cca0d81 3619 /*
3620 * Transfer data!
3621 */
0965bee0 3622 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 3623 ssh_send_ok = 1;
7cca0d81 3624 while (1) {
d211621f 3625 static int try_send;
e5574168 3626 crReturnV;
d211621f 3627 try_send = FALSE;
7cca0d81 3628 if (ispkt) {
3629 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3630 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3631 char *data;
3632 int length;
783415f8 3633 unsigned i = ssh2_pkt_getuint32();
3634 struct ssh_channel *c;
3635 c = find234(ssh_channels, &i, ssh_channelfind);
3636 if (!c)
3637 continue; /* nonexistent channel */
7cca0d81 3638 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3639 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3640 continue; /* extended but not stderr */
3641 ssh2_pkt_getstring(&data, &length);
d211621f 3642 if (data) {
783415f8 3643 switch (c->type) {
3644 case CHAN_MAINSESSION:
3645 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3646 data, length);
3647 break;
3648 case CHAN_X11:
3649 x11_send(c->u.x11.s, data, length);
3650 break;
36c2a3e9 3651 case CHAN_AGENT:
3652 while (length > 0) {
3653 if (c->u.a.lensofar < 4) {
3654 int l = min(4 - c->u.a.lensofar, length);
3655 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3656 data += l; length -= l; c->u.a.lensofar += l;
3657 }
3658 if (c->u.a.lensofar == 4) {
3659 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3660 c->u.a.message = smalloc(c->u.a.totallen);
3661 memcpy(c->u.a.message, c->u.a.msglen, 4);
3662 }
3663 if (c->u.a.lensofar >= 4 && length > 0) {
3664 int l = min(c->u.a.totallen - c->u.a.lensofar,
3665 length);
3666 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3667 data += l; length -= l; c->u.a.lensofar += l;
3668 }
3669 if (c->u.a.lensofar == c->u.a.totallen) {
3670 void *reply, *sentreply;
3671 int replylen;
3672 agent_query(c->u.a.message, c->u.a.totallen,
3673 &reply, &replylen);
3674 if (reply)
3675 sentreply = reply;
3676 else {
3677 /* Fake SSH_AGENT_FAILURE. */
3678 sentreply = "\0\0\0\1\5";
3679 replylen = 5;
3680 }
3681 ssh2_add_channel_data(c, sentreply, replylen);
3682 try_send = TRUE;
3683 if (reply)
3684 sfree(reply);
3685 sfree(c->u.a.message);
3686 c->u.a.lensofar = 0;
3687 }
3688 }
3689 break;
783415f8 3690 }
d211621f 3691 /*
783415f8 3692 * Enlarge the window again at the remote
3693 * side, just in case it ever runs down and
3694 * they fail to send us any more data.
d211621f 3695 */
3696 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 3697 ssh2_pkt_adduint32(c->remoteid);
d211621f 3698 ssh2_pkt_adduint32(length);
3699 ssh2_pkt_send();
3700 }
7cca0d81 3701 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3702 ssh_state = SSH_STATE_CLOSED;
d211621f 3703 logevent("Received disconnect message");
3257deae 3704 crReturnV;
7cca0d81 3705 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3706 continue; /* exit status et al; ignore (FIXME?) */
d211621f 3707 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 3708 unsigned i = ssh2_pkt_getuint32();
3709 struct ssh_channel *c;
3710
3711 c = find234(ssh_channels, &i, ssh_channelfind);
3712 if (!c)
3713 continue; /* nonexistent channel */
3714
3715 if (c->type == CHAN_X11) {
3716 /*
3717 * Remote EOF on an X11 channel means we should
3718 * wrap up and close the channel ourselves.
3719 */
3720 x11_close(c->u.x11.s);
3721 sshfwd_close(c);
36c2a3e9 3722 } else if (c->type == CHAN_AGENT) {
3723 sshfwd_close(c);
3724 }
d211621f 3725 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 3726 unsigned i = ssh2_pkt_getuint32();
3727 struct ssh_channel *c;
3728 enum234 e;
3729
3730 c = find234(ssh_channels, &i, ssh_channelfind);
3731 if (!c)
3732 continue; /* nonexistent channel */
3733 if (c->closes == 0) {
3734 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3735 ssh2_pkt_adduint32(c->remoteid);
3736 ssh2_pkt_send();
3737 }
3738 /* Do pre-close processing on the channel. */
3739 switch (c->type) {
3740 case CHAN_MAINSESSION:
3741 break; /* nothing to see here, move along */
3742 case CHAN_X11:
3743 break;
36c2a3e9 3744 case CHAN_AGENT:
3745 break;
783415f8 3746 }
3747 del234(ssh_channels, c);
3748 sfree(c->v2.outbuffer);
3749 sfree(c);
3750
3751 /*
3752 * See if that was the last channel left open.
3753 */
3754 c = first234(ssh_channels, &e);
3755 if (!c) {
d211621f 3756 logevent("All channels closed. Disconnecting");
3757 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 3758 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3759 ssh2_pkt_addstring("All open channels closed");
3760 ssh2_pkt_addstring("en"); /* language tag */
d211621f 3761 ssh2_pkt_send();
cf6e59d6 3762 ssh_state = SSH_STATE_CLOSED;
3257deae 3763 crReturnV;
d211621f 3764 }
3765 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 3766 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3767 unsigned i = ssh2_pkt_getuint32();
3768 struct ssh_channel *c;
3769 c = find234(ssh_channels, &i, ssh_channelfind);
3770 if (!c)
3771 continue; /* nonexistent channel */
0993479d 3772 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3773 try_send = TRUE;
783415f8 3774 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3775 char *type;
3776 int typelen;
3777 char *error = NULL;
3778 struct ssh_channel *c;
3779 ssh2_pkt_getstring(&type, &typelen);
3780 c = smalloc(sizeof(struct ssh_channel));
3781
3782 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 3783 if (!ssh_X11_fwd_enabled)
3784 error = "X11 forwarding is not enabled";
0c6c9a70 3785 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 3786 error = "Unable to open an X11 connection";
3787 } else {
3788 c->type = CHAN_X11;
3789 }
36c2a3e9 3790 } else if (typelen == 22 &&
3791 !memcmp(type, "auth-agent@openssh.com", 3)) {
3792 if (!ssh_agentfwd_enabled)
3793 error = "Agent forwarding is not enabled";
3794 else {
3795 c->type = CHAN_AGENT; /* identify channel type */
3796 c->u.a.lensofar = 0;
3797 }
783415f8 3798 } else {
3799 error = "Unsupported channel type requested";
3800 }
3801
3802 c->remoteid = ssh2_pkt_getuint32();
3803 if (error) {
3804 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3805 ssh2_pkt_adduint32(c->remoteid);
3806 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3807 ssh2_pkt_addstring(error);
3808 ssh2_pkt_addstring("en"); /* language tag */
3809 ssh2_pkt_send();
3810 sfree(c);
3811 } else {
3812 struct ssh_channel *d;
3813 unsigned i;
3814 enum234 e;
3815
3816 for (i=1, d = first234(ssh_channels, &e); d;
3817 d = next234(&e)) {
3818 if (d->localid > i)
3819 break; /* found a free number */
3820 i = d->localid + 1;
3821 }
3822 c->localid = i;
3823 c->closes = 0;
3824 c->v2.remwindow = ssh2_pkt_getuint32();
3825 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3826 c->v2.outbuffer = NULL;
3827 c->v2.outbuflen = c->v2.outbufsize = 0;
3828 add234(ssh_channels, c);
3829 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3830 ssh2_pkt_adduint32(c->remoteid);
3831 ssh2_pkt_adduint32(c->localid);
3832 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3833 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3834 ssh2_pkt_send();
3835 }
7cca0d81 3836 } else {
8d5de777 3837 bombout(("Strange packet received: type %d", pktin.type));
3838 crReturnV;
7cca0d81 3839 }
3840 } else {
d211621f 3841 /*
3842 * We have spare data. Add it to the channel buffer.
3843 */
783415f8 3844 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 3845 try_send = TRUE;
7cca0d81 3846 }
d211621f 3847 if (try_send) {
783415f8 3848 enum234 e;
3849 struct ssh_channel *c;
d211621f 3850 /*
783415f8 3851 * Try to send data on all channels if we can.
d211621f 3852 */
783415f8 3853 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3854 ssh2_try_send(c);
d211621f 3855 }
e5574168 3856 }
3857
3858 crFinishV;
3859}
3860
3861/*
7cca0d81 3862 * Handle the top-level SSH2 protocol.
3863 */
3864static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3865{
3866 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3867 return;
3868 do_ssh2_authconn(in, inlen, ispkt);
3869}
3870
3871/*
8df7a775 3872 * Called to set up the connection.
374330e2 3873 *
3874 * Returns an error message, or NULL on success.
374330e2 3875 */
8df7a775 3876static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3877 char *p;
8f203108 3878
3879#ifdef MSCRYPTOAPI
3880 if(crypto_startup() == 0)
3881 return "Microsoft high encryption pack not installed!";
3882#endif
374330e2 3883
8df7a775 3884 ssh_send_ok = 0;
0965bee0 3885 ssh_editing = 0;
3886 ssh_echoing = 0;
8df7a775 3887
fb09bf1c 3888 p = connect_to_host(host, port, realhost);
3889 if (p != NULL)
3890 return p;
374330e2 3891
374330e2 3892 return NULL;
3893}
3894
3895/*
374330e2 3896 * Called to send data down the Telnet connection.
3897 */
3898static void ssh_send (char *buf, int len) {
f78051a1 3899 if (s == NULL || ssh_protocol == NULL)
374330e2 3900 return;
3901
3902 ssh_protocol(buf, len, 0);
3903}
3904
3905/*
6e48c3fe 3906 * Called to set the size of the window from SSH's POV.
374330e2 3907 */
3908static void ssh_size(void) {
3909 switch (ssh_state) {
3910 case SSH_STATE_BEFORE_SIZE:
3687d221 3911 case SSH_STATE_PREPACKET:
21248260 3912 case SSH_STATE_CLOSED:
374330e2 3913 break; /* do nothing */
3914 case SSH_STATE_INTERMED:
3915 size_needed = TRUE; /* buffer for later */
3916 break;
3917 case SSH_STATE_SESSION:
fef97f43 3918 if (!cfg.nopty) {
6e48c3fe 3919 if (ssh_version == 1) {
3920 send_packet(SSH1_CMSG_WINDOW_SIZE,
3921 PKT_INT, rows, PKT_INT, cols,
3922 PKT_INT, 0, PKT_INT, 0, PKT_END);
3923 } else {
3924 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3925 ssh2_pkt_adduint32(mainchan->remoteid);
3926 ssh2_pkt_addstring("window-change");
3927 ssh2_pkt_addbool(0);
3928 ssh2_pkt_adduint32(cols);
3929 ssh2_pkt_adduint32(rows);
3930 ssh2_pkt_adduint32(0);
3931 ssh2_pkt_adduint32(0);
3932 ssh2_pkt_send();
3933 }
fef97f43 3934 }
3687d221 3935 break;
374330e2 3936 }
3937}
3938
3939/*
6abbf9e3 3940 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3941 * can send an EOF and collect resulting output (e.g. `plink
3942 * hostname sort').
374330e2 3943 */
3944static void ssh_special (Telnet_Special code) {
6abbf9e3 3945 if (code == TS_EOF) {
3687d221 3946 if (ssh_state != SSH_STATE_SESSION) {
3947 /*
3948 * Buffer the EOF in case we are pre-SESSION, so we can
3949 * send it as soon as we reach SESSION.
3950 */
3951 if (code == TS_EOF)
3952 eof_needed = TRUE;
3953 return;
3954 }
67779be7 3955 if (ssh_version == 1) {
6abbf9e3 3956 send_packet(SSH1_CMSG_EOF, PKT_END);
3957 } else {
3958 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3959 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3960 ssh2_pkt_send();
3961 }
67779be7 3962 logevent("Sent EOF message");
ec55b220 3963 } else if (code == TS_PING) {
3687d221 3964 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3965 return;
ec55b220 3966 if (ssh_version == 1) {
3967 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3968 } else {
3969 ssh2_pkt_init(SSH2_MSG_IGNORE);
3970 ssh2_pkt_addstring_start();
3971 ssh2_pkt_send();
3972 }
6abbf9e3 3973 } else {
3974 /* do nothing */
3975 }
374330e2 3976}
3977
8df7a775 3978static Socket ssh_socket(void) { return s; }
8ccc75b0 3979
3980static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3981
0965bee0 3982static int ssh_ldisc(int option) {
3983 if (option == LD_ECHO) return ssh_echoing;
3984 if (option == LD_EDIT) return ssh_editing;
3985 return FALSE;
3986}
3987
374330e2 3988Backend ssh_backend = {
3989 ssh_init,
374330e2 3990 ssh_send,
3991 ssh_size,
4017be6d 3992 ssh_special,
8ccc75b0 3993 ssh_socket,
97db3be4 3994 ssh_sendok,
0965bee0 3995 ssh_ldisc,
97db3be4 3996 22
374330e2 3997};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator